3434.45251134.453634.4541071134.4551211.01848131234.45691434.4572101634.4581134.4591234.460135034.4611434.462153.117.134.46316213.217.234.4641734.46518522234.46619134.4672034.4682134.4692234.47023334.4714244true534.4722518634.4737262834.47432794334.4751028251134.4764295.112534.47713302061434.47831true1513234.47916321815182234.48015.13312034.48121342234.4823522237.0134.4832.0024367.02262.017.0334.48437282.027.0434.48529382.037.0634.38434.52034.31634.18014.001840.01109.140.017614.001940.011140.017734.5219.1134.31734.38534.18114.00209.1240.011240.017834.18234.5221634.31834.38614.00219.1314.002240.01131740.017934.5239.1434.31934.38734.18314.00239.1540.011440.018034.18434.52434.32034.38814.00249.1614.002540.011540.018134.52534.32134.38934.18514.002640.011640.018234.18634.526834.32234.39014.002723714.002840.011740.01832434.52734.32334.39134.18740.011840.018434.18834.52834.32434.39240.011940.018534.18934.52934.32534.39340.012040.018634.53034.32634.39434.19040.018734.19134.53134.32734.39514.004340.018834.53234.32834.39634.19214.0044140.018934.53314.004534.32934.39734.193214.004640.019034.53434.33034.39834.194314.02914.0047440.019134.19534.39914.03034.53514.004834.331714.03114.004940.019234.53634.33234.40034.196814.03214.0050940.019314.03334.53714.005134.33334.40134.19712414.03414.005240.019434.19834.53834.33434.40231314.03514.00531440.019534.19914.03634.54014.005434.33534.40351514.03714.005540.019634.200634.59834.33634.4041814.03814.0056191940.019714.008534.20114.03934.33734.40522014.008614.04140.0198334.33834.40634.2022314.008742440.019914.009234.33934.40734.20352514.009340.0200634.34034.40834.2042614.0094714.009534.34134.40934.205814.000114.0096914.000234.34234.41034.20614.00971014.000314.009834.34334.41134.20711114.00041214.0005234.34434.41234.2081314.00063Montana Operations34.34534.41334.2091414.000741514.0008534.34634.41434.2101614.0009634.34734.41534.2111714.001071814.0011834.34834.41634.2121914.0012934.34934.41734.2132014.00131014.002914.0069934.24834.1123114.0070641034.24934.11326.01351134.25034.11436.02166.031234.25134.1156176.04921334.25234.11686.053106.061434.25334.11740.008191146.071340.0082101534.25434.11856.081540.00836.091634.25534.1191666.101840.00841734.25634.1207740.00857.011834.25734.12187.0240.00861934.25834.122940.00872034.25934.1231040.00882134.26034.1241140.00892234.26134.1251240.00902334.26234.12613240.00912434.263434.127141540.00922534.26434.128156340.00932634.265734.1294168540.00942734.26634.130176840.00952834.26734.1317187840.00962934.26834.132199940.00973034.26934.133101020111140.00983234.27034.13422112140.00993334.27134.1352232340.01003434.27234.136234440.010134.00134.27334.1375245640.010234.00234.27434.1382540.010334.00334.27534.1392640.010434.00434.27634.1402714.01540.010534.00534.27734.1412814.01640.010634.00634.27834.14214.0172914.01840.010734.00734.27934.1433014.01940.010834.00834.28034.14414.0203114.02140.010934.00934.28134.1453214.02240.02142.0434.04440.002640.00683913.0840.013440.02152.0540.006940.013534.04540.0027402.0640.0216540.007040.01362.0734.04640.002840.021762.083440.007140.013734.047South Dakota Operations40.00292.0940.021840.007240.013840.00302.1034.04840.02192.1140.007340.013934.04940.00312.1240.022040.007440.014040.00322.1334.05040.02212.1440.007540.014134.05140.00332.1540.02223640.007640.01422.1634.05240.003440.02232.1740.007740.014334.05340.00352.1840.022440.007840.01442.1934.05440.0036false40.02252.2040.007940.014534.05540.00372.2140.022640.008040.01463.0034.05640.003840.02273.013840.014734.05740.00393.0240.022840.01483.0334.05840.004040.02293.0440.014934.059440.023040.015034.06040.023140.015134.06140.02324040.015234.06240.023340.015334.063C00178940.023440.015434.06440.023540.015534.06540.023640.015634.06640.02374240.015734.06740.023840.015834.068O40.0239146840.01597834.069677740.024040.016034.070798434.0719685441034.07271134.0731287715.0197934.07415.021034.07515.03Not Prepared34.07624634.077134.41834.486134.41934.4872334.42034.48824134.42134.4895334.42234.4904634.42334.49157634.42434.4927834.42534.49389934.42634.494101034.42734.49511111234.42834.4961234.42934.4971334.43034.4981434.43134.4991534.43234.50034.43334.50135.00134.43434.50235.00234.43534.50335.00334.43634.50435.03340.016134.43734.50540.016234.43834.50640.016334.43934.50740.016434.44034.50840.016534.44134.509840.016634.44234.51040.016734.44334.51140.016834.44434.51240.016934.44534.51340.017034.44634.5149.0140.01719.0234.44734.5159.0340.017234.44834.5169.04140.017334.4499.0534.517119.0640.0174234.45034.5189.07340.01759.0834.45134.51949.092114.0014134.35034.21414.0030214.003134.35134.21514.0032334.35234.21614.0033414.003434.35334.217614.003534.35434.218714.003614.0037834.35534.21914.0038934.35634.22014.00391014.004034.35734.2211114.00414451419234.35834.22214.00421234.35934.22313115389841434.36034.2241534.36134.2251634.362134.22617101.0134.36334.22718111.0234.36434.22819121.03131.042034.36534.229234.36634.2302.012134.36734.2312132034.36834.232422534.36934.2332362434.37034.234725834.37134.23526934.37234.236101134.37334.2371234.37434.238131434.37534.239153334.37634.24016343534.37734.24134.37834.24234.37934.2431.021.0134.38034.24434.38134.24534.38234.24614.001514.001634.38334.24714.00171134.28234.07834.1467.0814.02333127.0914.02434.28334.07934.14734137.114.0251434.28434.08034.1487.1114.02635157.1214.02734.28534.08134.149167.1314.0281734.28634.08234.1507.14187.1534.28734.08334.151197.1634.2882034.08434.1527.17217.1840.004114.007134.28934.08534.1532214.007240.00422634.29034.08634.15414.00732940.004314.007434.29134.08734.1553014.007540.00443234.29234.08834.15614.007640.004514.007734.29334.08934.15714.007840.004634.29434.09034.15814.007940.004714.008034.29534.09134.15914.008140.004834.29634.09234.16014.008240.004914.008334.29734.09334.16114.008440.005034.29834.09434.16240.005134.29934.09534.16340.005234.30034.09634.16440.005334.30134.09734.165240.0054101The Workiva Platform34.30234.09834.166340.005534.30334.09934.167440.0056534.30434.10034.168640.005734.30534.10134.169740.0058834.30634.10234.170940.00591234.30734.10334.1711040.006014.00571134.30834.10434.1722014.00581240.006134.17334.30934.1052014.00591340.006214.00601434.31034.10634.17414.006140.0063234.17534.31134.107314.006240.0064413.0114.006334.31234.10834.17613.0214.006440.006534.31313.0334.10934.17714.006540.006613.0414.006634.31434.11034.17813.0514.006740.006734.31513.0634.11134.17914.006813.0734.01034.0112434.012334.01334.01414.00140.024134.01540.0242134.01640.024325.1234.01725.2340.024414.002434.01814.003140.024514.004534.019440.000140.024614.005514.006634.02040.0002640.024714.00734.021740.00031040.024814.00881134.02240.000414.009940.024914.01034.0231040.000540.025014.0111114.009814.01234.02440.00061240.025114.009914.01334.0251340.00072614.010040.025214.0141414.010134.02640.000840.025314.010334.02740.0009440.0254334.02840.001040.025534.02940.001140.025634.03040.001227.240.025740.020134.03140.001340.012140.02022840.012234.03240.001440.020340.012334.03340.001540.0204111240.012434.03440.001640.020540.012534.03540.001740.020640.012634.03640.001840.02073040.012734.03740.0019140.0208240.012834.03840.0020340.020940.012934.03940.0021440.02101840.013034.0401940.0022540.021119.0140.013134.04140.0023619.0240.02123240.013234.04219.0340.0024740.021340.013334.04340.00258 C001789 Bridger Auto (BILLINGS), Transmission, Unattended 2023-12-31 C001789 ferc:LandAndRightsMember Missoula Miller Creek Sub site 2023-01-012023-12-31 C001789 ferc:PaidInCapitalMember Canadian Montana Pipeline Corporation - Paid in Capital 2022-12-31 C001789 Mill Creek Generating (BUTTE), Transmission, Unattended 2023-12-31 C001789 Bleau Lafave (VP Asset 2023-01-012023-12-31 C001789 Morgan Stanley Capital Group, Inc. NWMT GWA NF MONTANA OATT COLSTRIP GLWND1 2023-01-012023-12-31 C001789 Federal Unemplyment Tax, Unemployment Tax, Montana, 2022 2023-01-012023-12-31 C001789 Huron Gas Turbine Plant A (SD), Transmission, Unattended 2023-01-012023-12-31 C001789 ferc:PenaltyTaxMember 2022-12-31 C001789 Total South Dakota 2023-01-012023-12-31 C001789 ferc:LandAndRightsMember Billings Metra Sub Site 2023-12-31 C001789 Harlem (HAVRE), Transmission, Unattended 2023-01-012023-12-31 C001789 Avangrid Renewables, LLC , SF, Market-Based Rate 2023-01-012023-12-31 C001789 Projects & Studies Prepaid by Customers (Montana) 2022-12-31 C001789 Thompson Falls City (MISSOULA), Distribution, Unattended 2023-01-012023-12-31 C001789 ferc:ElectricUtilityMember 2022-01-012022-12-31 C001789 ferc:OtherTaxesAndFeesMemberferc:ElectricUtilityMember 2023-01-012023-12-31 C001789 Vitol Inc. BPAT NWMT NF MONTANA OATT BPAT.NWMT MATL.NWMT 2023-01-012023-12-31 C001789 Aberdeen NE Gas Plant B (SD), Distribution, Unattended 2023-01-012023-12-31 C001789 First Mortgage Bonds 2.66% (South Dakota) 2023-12-31 C001789 Property Tax, Property Tax, North Dakota, 2022 2023-12-31 C001789 Miscellaneous 2023-01-012023-12-31 C001789 Annual Charges Under the Omnibus 2023-01-012023-12-31 C001789 Strawberry Creek (NON TIER II QF-1), LU, 2023-01-012023-12-31 C001789 ferc:MayMember South Dakota Operations 2023-01-012023-12-31 C001789 Other Debit or Cr. Items (Describe, details in footnote): 2023-01-012023-12-31 C001789 South Butte B (BUTTE), Transmission, Unattended 2023-01-012023-12-31 C001789 South Dakota Operations: 2023-01-012023-12-31 C001789 Lake 2023-01-012023-12-31 C001789 NorthWestern Energy Solutions, Inc. 2023-12-31 C001789 Morgan Stanley Capital Group, Inc. BPAT NWMT SFP MONTANA OATT BPAT.NWMT MATL.NWMT 2023-01-012023-12-31 C001789 Judith Gap Auto (BILLINGS), Transmission, Unattended 2023-01-012023-12-31 C001789 Basin Electric Power Cooperative NWMT WAUW NF MONTANA OATT MATL.NWMT GREATFALLS 2023-01-012023-12-31 C001789 Morgan Stanley Capital Group, Inc. PPW BPAT SFP MONTANA OATT BRDY BPAT.NWMT 2023-01-012023-12-31 C001789 Pension Requirement (South Dakota) 2023-12-31 C001789 Line Interconnection Studies 2023-01-012023-12-31 C001789 ferc:OtherTaxesAndFeesMember 2023-12-31 C001789 Interest Rate Hedge Amortizations 2023-01-012023-12-31 C001789 Excess Deferred Income Taxes (South Dakota) 2023-01-012023-12-31 C001789 Minor Projects (Less than $250,000 - 18 items) 2023-01-012023-12-31 C001789 Other Minor Items (4) - some are amortized over various periods (South Dakota) 2022-12-31 C001789 Anthony T. Clark 2023-01-012023-12-31 C001789 Whatley (HAVRE), Transmission, Unattended 2023-01-012023-12-31 C001789 MAG Energy Solutions NWMT PACE SFP MONTANA OATT MATL.NWMT BRDY 2023-01-012023-12-31 C001789 ferc:FederalInsuranceTaxMemberferc:ElectricUtilityMember 2023-01-012023-12-31 C001789 Puget Sound Energy Marketing AVA MLCK NF MONTANA OATT COLSTRIP MLCK 2023-01-012023-12-31 C001789 Mitchell NW (SD), Transmission, Unattended 2023-12-31 C001789 ferc:OtherUtilityOrNonutilityMember Other - 30% 2023-01-012023-12-31 C001789 Excess Deferred Income Taxes (Montana) 2023-01-012023-12-31 C001789 EELT Tax, Other Taxes, Montana, 2022 2023-01-012023-12-31 C001789 Portland General Electric Company BPAT NWMT NF MONTANA OATT BPAT.NWMT NWMT.SYSTEM 2023-01-012023-12-31 C001789 Shell Energy North America BPAT PPW NF MONTANA OATT BPAT.NWMT YTP 2023-01-012023-12-31 C001789 Morgan Stanley Capital Group, Inc. NWMT PACE SFP MONTANA OATT MATL.NWMT BRDY 2023-01-012023-12-31 C001789 First Mortgage Bonds 4.03% (Montana) 2023-01-012023-12-31 C001789 Sun River Elect Coop OLF 2023-01-012023-12-31 C001789 First Mortgage Bonds 3.99% (Montana) 2023-01-012023-12-31 C001789 Common Stock Dividend 2023-01-012023-12-31 C001789 Basin Creek Capital Lease (Montana) 2022-12-31 C001789 CP Energy Marketing (US) Inc. BPAT NWMT NF MONTANA OATT BPAT.NWMT MATL.NWMT 2023-01-012023-12-31 C001789 Aberdeen Ethanol (SD), Distribution, Unattended 2023-01-012023-12-31 C001789 The Energy Authority BPAT NWMT NF MONTANA OATT BPAT.NWMT MATL.NWMT 2023-01-012023-12-31 C001789 Yankton City (SD), Distribution, Unattended 2023-01-012023-12-31 C001789 Macquarie Energy, LLC PPW BPAT SFP MONTANA OATT YTP BPAT.NWMT 2023-01-012023-12-31 C001789 ferc:ElectricUtilityMember 2023-12-31 C001789 500 kV Operations - Partner's Share (Montana) 2022-12-31 C001789 Shell Energy North America BPAT NWMT NF MONTANA OATT BPAT.NWMT NWMT.SYSTEM 2023-01-012023-12-31 C001789 Morgan Stanley Capital Group, Inc. NWMT BPAT NF MONTANA OATT JUDITHGAP BPAT.NWMT 2023-01-012023-12-31 C001789 Kent T. Larson 2023-01-012023-12-31 C001789 Kershaw Switchyard (GREAT FALLS), Transmission, Unattended 2023-12-31 C001789 West Central Elect COOP FNS 2023-01-012023-12-31 C001789 Total Yellowstone Park 2023-01-012023-12-31 C001789 ferc:GasUtilityMember Unbilled Revenue 2022-12-31 C001789 Altop Energy Trading LLC PPW WAPA NF MONTANA OATT BRDY CROSSOVER 2023-01-012023-12-31 C001789 Montana Operationsferc:AugustMember 2023-01-012023-12-31 C001789 Tripp Jct. (SD), Transmission, Unattended 2023-12-31 C001789 ferc:OtherTaxesAndFeesMember 2022-12-31 C001789 Energy Keepers Inc. NWMT BPAT NF MONTANA OATT MATL.NWMT BPAT.NWMT 2023-01-012023-12-31 C001789 Huron Gas Turbnie Plant B (SD), Transmission, Unattended 2023-01-012023-12-31 C001789 First Mortgage Bonds 4.30% (Montana) 2023-01-012023-12-31 C001789 Morgan Stanley Capital Group, Inc. GWA AVA SFP MONTANA OATT GLWND1 AVAT.NWMT 2023-01-012023-12-31 C001789 South Peak Wind (NON TIER II QF-1), LU, 2023-01-012023-12-31 C001789 Generating Stations Under Project License 2023-01-012023-12-31 C001789 Landers Fork (HELENA), Distribution, Unattended 2023-01-012023-12-31 C001789 Rainbow Electric Marketing Corp. PACE NWMT NF MONTANA OATT YTP MATL.NWMT 2023-01-012023-12-31 C001789 All 69 kV, , Various, 2023-01-012023-12-31 C001789 ferc:IncomeTaxMember 2023-01-012023-12-31 C001789 Shell Energy North America BPAT WAPA SFP MONTANA OATT BPAT.NWMT CROSSOVER 2023-01-012023-12-31 C001789 MT Residential 2023-01-012023-12-31 C001789 Morgan Stanley Capital Group, Inc. WAUW NWMT NF MONTANA OATT CROSSOVER MATL.NWMT 2023-01-012023-12-31 C001789 ferc:SulfurDioxideMemberferc:ThreeYearsMember 2023-12-31 C001789 Oak Tree (PPA Wind #2) (SOUTH DAKOTA PURCHASES), LU, 2023-01-012023-12-31 C001789 MT Irrigation 2023-01-012023-12-31 C001789 ferc:SulfurDioxideMember 2023-12-31 C001789 Platte A (SD), Distribution, Unattended 2023-12-31 C001789 Gross Receipts Tax, Other Taxes, South Dakota, 2023 2023-12-31 C001789 MAG Energy Solutions WAPA PPW NF MONTANA OATT CROSSOVER BRDY 2023-01-012023-12-31 C001789 Johnson Lane (BILLINGS), Distribution, Unattended 2023-01-012023-12-31 C001789 Projects & Studies Prepaid by Customers (Montana) 2023-01-012023-12-31 C001789 Stickney Jct. (SD), Transmission, Unattended 2023-01-012023-12-31 C001789 ferc:GasUtilityMember Pension/Postretirement Benefits 2023-12-31 C001789 ferc:OtherAllocatedTaxMember 2023-01-012023-12-31 C001789 Colstrip City (BILLINGS), Transmission, Unattended 2023-01-012023-12-31 C001789 Guzman Energy, LLC WAPA PPW NF MONTANA OATT CROSSOVER YTP 2023-01-012023-12-31 C001789 Puget Sound Energy Marketing BPAT NWMT NF MONTANA OATT BPAT.NWMT COLSTRIP 2023-01-012023-12-31 C001789 California Independent System Operator - EIM Transmission (PURCHASED POWER SUPPLY), SF, CAISO 2023-01-012023-12-31 C001789 Hanover Hydro (NON TIER II QF-1), LU, 2023-01-012023-12-31 C001789 ferc:IncomeTaxMember 2023-12-31 C001789 PacifiCorp PPW NWMT SFP MONTANA OATT MLCK JEFF 2023-01-012023-12-31 C001789 Redfield D (SD), Transmission, Unattended 2023-01-012023-12-31 C001789 2023-01-012023-09-30 C001789 Great Falls Northeast (GREAT FALLS), Distribution, Unattended 2023-01-012023-12-31 C001789 ferc:OtherLicenseAndFeesTaxMember 2023-12-31 C001789 ferc:OtherStateTaxMember 2022-12-31 C001789 Richardson Coulee (HAVRE), Transmission, Unattended 2023-01-012023-12-31 C001789 SociVolta, Inc. PACE NWMT NF MONTANA OATT BRDY MATL.NWMT 2023-01-012023-12-31 C001789 First Mortgage Bonds 4.15% (South Dakota) 2023-12-31 C001789 ferc:ExciseTaxMember 2022-12-31 C001789 The Energy Authority AVA PPW NF MONTANA OATT AVAT.NWMT BRDY 2023-01-012023-12-31 C001789 First Mortgage Bonds 4.03% (Montana) 2023-12-31 C001789 ScheduleTransmissionLinesAddedAbstract 2023-01-012023-12-31 C001789 Basin Electric Power Cooperative Basin Electric & WAPA Basin Electric Power Cooperative FNO Montana OATT BPAT.NWMT & Great Falls Various NWMT & WAUW 2023-01-012023-12-31 C001789 ferc:GasUtilityMember 2023-12-31 C001789 Treasury Stock Activity 2023-01-012023-12-31 C001789 Puget Sound Energy Marketing NWMT BPAT SFP MONTANA OATT COLSTRIP BPAT.NWMT 2023-01-012023-12-31 C001789 ferc:GasUtilityMember Compensation Accruals 2022-12-31 C001789 Dynasty Power Inc. PPW BPAT NF MONTANA OATT YTP BPAT.NWMT 2023-01-012023-12-31 C001789 Butte Cora (BUTTE), Distribution, Unattended 2023-12-31 C001789 Big Stone Plant A (SD), Transmission, Unattended 2023-01-012023-12-31 C001789 Aberdeen Industrial Park (SD), Distribution, Unattended 2023-12-31 C001789 FERC Order No. 472 2023-01-012023-12-31 C001789 Basin Electric Power Cooperative PPW WAPA SFP MONTANA OATT YTP CROSSOVER 2023-01-012023-12-31 C001789 Canadian Montana Pipeline Corporation - Translation Adjustmentferc:OtherInvestmentsInSubsidiaryCompaniesMember 2022-12-31 C001789 Risk Partners Assurance, Ltd. 2023-01-012023-12-31 C001789 Permanent Uncertain Tax Positions (Montana) 2023-01-012023-12-31 C001789 Energy Keepers, Inc. (PURCHASED POWER SUPPLY), SF, Market-Based Rate Tariff 2023-01-012023-12-31 C001789 Heavy Highway Tax, Other Taxes, South Dakota, 2023ferc:ElectricUtilityMember 2023-01-012023-12-31 C001789 Morgan Stanley Capital Group, Inc. GWA PPW NF MONTANA OATT GLWND1 BRDY 2023-01-012023-12-31 C001789 Meridian (BILLINGS), Distribution, Unattended 2023-12-31 C001789 Oil DGGS 2023-01-012023-12-31 C001789 Big Sky Midway B (BOZEMAN), Distribution, Unattended 2023-12-31 C001789 Two Dot 2023-01-012023-12-31 C001789 Redfield C (SD), Transmission, Unattended 2023-12-31 C001789 Transmission Line Rights (Montana) 2023-01-012023-12-31 C001789 ferc:NitrogenOxideMember Allowances Used 2023-01-012023-12-31 C001789 Federal Income Tax, Income Tax, Montana, 2023 2023-12-31 C001789 Big Timber Auto (BOZEMAN), Transmission, Unattended 2023-12-31 C001789 ferc:OtherUseTaxMember 2023-01-012023-12-31 C001789 Excess Tax Depreciation 2023-01-012023-12-31 C001789 Constellation Energy Generation, LLC , SF, Market-Based Rate 2023-01-012023-12-31 C001789 Mobile 8 2023-01-012023-12-31 C001789 Dynasty Power, Inc. (PURCHASED POWER SUPPLY), SF, Market-Based Rate Tariff 2023-01-012023-12-31 C001789 Southwest Power Pool (MT) FNS 2023-01-012023-12-31 C001789 Basin Creek Capital Lease (Montana) 2023-01-012023-12-31 C001789 Morgan Stanley Capital Group, Inc. GWA BPAT NF MONTANA OATT GLWND2 BPAT.NWMT 2023-01-012023-12-31 C001789 Aberdeen 8th Avenue (SD), Distribution, Unattended 2023-01-012023-12-31 C001789 Billings Eighth Street (BILLINGS), Transmission, Unattended 2023-12-31 C001789 Heavy Highway Tax, Other Taxes, Montana, 2023 2023-12-31 C001789 Huron City A (SD), Distribution, Unattended 2023-01-012023-12-31 C001789 Guzman Energy, LLC  (PURCHASED POWER SUPPLY), SF, Market-Based Rate Tariff 2023-01-012023-12-31 C001789 Great Falls Public Schools Energy Keepers Inc. Great Falls Public Schools FNO Montana OATT Kerr Great Falls, MT 2023-01-012023-12-31 C001789 Transalta Energy Marketing (US) Inc. 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BPAT WAPA NF MONTANA OATT BPAT.NWMT CROSSOVER 2023-01-012023-12-31 C001789 Personal Property - Auto, Other Taxes, Montana, 2023ferc:ElectricUtilityMember 2023-01-012023-12-31 C001789 Dynasty Power Inc. PPW NWMT NF MONTANA OATT BRDY GTFALLSNWMT 2023-01-012023-12-31 C001789 Naturener Power Watch, LLC GWA GWA SFP MONTANA OATT GLWND1 GLWND2 2023-01-012023-12-31 C001789 Unamortized Debt Expense (South Dakota) 2022-12-31 C001789 First Mortgage Bonds 5.01% (South Dakota) 2023-12-31 C001789 7% 2023-01-012023-12-31 C001789 FEA Studies 2023-01-012023-12-31 C001789 Oil Big Stone 2023-01-012023-12-31 C001789 Drummond City (BUTTE), Transmission, Unattended 2023-01-012023-12-31 C001789 Mobile 3 2023-12-31 C001789 Macquarie Energy, LLC PPW BPAT NF MONTANA OATT BRDY BPAT.NWMT 2023-01-012023-12-31 C001789 Shell Energy North America NWMT WAUW NF MONTANA OATT BGI GREATFALLS 2023-01-012023-12-31 C001789 WAPA Broadland (SD), Transmission, Unattended 2023-12-31 C001789 Macquarie Energy, LLC NWMT NWMT SFP MONTANA OATT TFALLS NWMT.SYSTEM 2023-01-012023-12-31 C001789 Asset Retirement Obligation (Montana) 2023-01-012023-12-31 C001789 Judith Gap South (BILLINGS), Transmission, Unattended 2023-01-012023-12-31 C001789 Administration Fee, Havre Pipeline Company, LLC 2023-01-012023-12-31 C001789 Great Falls Southside (GREAT FALLS), Distribution, Unattended 2023-01-012023-12-31 C001789 TEC Energy Inc. PACE NWMT NF MONTANA OATT YTP MATL.NWMT 2023-01-012023-12-31 C001789 Aberdeen Fairgrounds (SD), Distribution, Unattended 2023-01-012023-12-31 C001789 Rainbow Electric Marketing Corp. WAUW NWMT NF MONTANA OATT CROSSOVER MATL.NWMT 2023-01-012023-12-31 C001789 Huron West Park B (SD), Transmission, Unattended 2023-01-012023-12-31 C001789 MAG Energy Solutions PACE NWMT NF MONTANA OATT BRDY MATL.NWMT 2023-01-012023-12-31 C001789 Other Minor Items (4) - some are amortized over various periods (South Dakota) 2023-01-012023-12-31 C001789 Macquarie Energy, LLC PPW BPAT SFP MONTANA OATT BRDY BPAT.NWMT 2023-01-012023-12-31 C001789 EDF Trading North America, LLC NWMT BPAT NF MONTANA OATT COLSTRIP BPAT.NWMT 2023-01-012023-12-31 C001789 Shell Energy North America BPAT PPW NF MONTANA OATT BPAT.NWMT BRDY 2023-01-012023-12-31 C001789 Transalta Energy Marketing (US) Inc. WAPA PPW SFP MONTANA OATT CROSSOVER YTP 2023-01-012023-12-31 C001789 Highmore ER Interconnect (SD), Transmission, Unattended 2023-01-012023-12-31 C001789 Belgrade West (BOZEMAN), Transmission, Unattended 2023-12-31 C001789 First Mortgage Bonds 4.85% (South Dakota) 2023-01-012023-12-31 C001789 Lake 2023-12-31 C001789 Malta Auto (HAVRE), Transmission, Unattended 2023-01-012023-12-31 C001789 Mill Creek A (BUTTE), Transmission, Unattended 2023-01-012023-12-31 C001789 Huron Gas Turbnie Plant B (SD), Transmission, Unattended 2023-12-31 C001789 ferc:OtherFederalTaxMember 2023-01-012023-12-31 C001789 General Mills Operations, LLC Talen Energy General Mills Operations, LLC FNO Montana OATT Colstrip Great Falls, MT 2023-01-012023-12-31 C001789 QUALIFYING FACILITIES, , 2023-01-012023-12-31 C001789 ferc:ElectricUtilityMember 2023-01-012023-12-31 C001789 ferc:ElectricUtilityMemberferc:GeneralPlantMember 2023-01-012023-12-31 C001789 Federal Income Tax, Income Tax, Montana, 2023 2022-12-31 C001789 Powerex Corporation BPAT AVA NF MONTANA OATT BPAT.NWMT AVAT.NWMT 2023-01-012023-12-31 C001789 Townsend (HELENA), Distribution, Unattended 2023-12-31 C001789 Morgan Stanley Capital Group, Inc. 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NWMT NWMT NF MONTANA OATT COLSTRIP NWMT.SYSTEM 2023-01-012023-12-31 C001789 Phillips 66 Energy Trading, LLC NWMT AVA SFP MONTANA OATT COLSTRIP AVAT.NWMT 2023-01-012023-12-31 C001789 Montana State University - Bozeman WAPA Montana State University - Bozeman FNO Montana OATT Fort Peck West Great Falls, MT 2023-01-012023-12-31 C001789 ferc:OtherFederalTaxMember 2022-12-31 C001789 Morgan Stanley Capital Group, Inc. WAPA AVA NF MONTANA OATT GREATFALLS AVAT.NWMT 2023-01-012023-12-31 C001789 Belgrade West (BOZEMAN), Transmission, Unattended 2023-01-012023-12-31 C001789 Dynasty Power Inc. 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BPAT NWMT NF MONTANA OATT BPAT.NWMT MATL.NWMT 2023-01-012023-12-31 C001789 Aspen Air U.S., LLC Talen Energy Aspen Air Corporation FNO Montana OATT Colstrip  Billings, MT 2023-01-012023-12-31 C001789 ferc:LandAndRightsMember Missoula Miller Creek Sub site 2023-12-31 C001789 (Less) (449.1) Provision for Rate Refunds 2023-01-012023-12-31 C001789 Morgan Stanley Capital Group, Inc. 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AVA NWMT NF MONTANA OATT AVAT.NWMT MATL.NWMT 2023-01-012023-12-31 C001789 Basin Electric Power Cooperative PPW PPW NF MONTANA OATT BRDY MLCK 2023-01-012023-12-31 C001789 Rainbow Electric Marketing Corp. PPW WAPA SFP MONTANA OATT YTP CROSSOVER 2023-01-012023-12-31 C001789 First Mortgage Bonds 5.71% (Montana) 2023-12-31 C001789 Consumer Counsel, Other Taxes, Montana, 2023 2023-12-31 C001789 Guzman Energy, LLC WAPA NWMT NF MONTANA OATT GREATFALLS NWMT.SYSTEM 2023-01-012023-12-31 C001789 Pension Plan (South Dakota) 2022-12-31 C001789 Property Tax, Property Tax, Iowa, 2023 2023-01-012023-12-31 C001789 Billings Conoco (BILLINGS), Distribution, Unattended 2023-12-31 C001789 Morgan Stanley Capital Group, Inc. 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BPAT PPW NF MONTANA OATT BPAT.NWMT BRDY 2023-01-012023-12-31 C001789 Transalta Energy Marketing (US) Inc. PPW PPW NF MONTANA OATT YTP ANTE 2023-01-012023-12-31 C001789 Billings Steam Plant Switchyard A (BILLINGS), Distribution, Unattended 2023-01-012023-12-31 C001789 Glengarry (BILLINGS), Transmission, Unattended 2023-12-31 C001789 Rainbow Energy Marketing Corporation (PURCHASED POWER SUPPLY), SF, Market-Based Rate Tariff 2023-01-012023-12-31 C001789 Morgan Stanley Capital Group, Inc. 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Horsfall 2023-01-012023-12-31 C001789 FICA and Medicare, Federal Tax, South Dakota, 2023 2023-12-31 C001789 BONNEVILLE POWER ADMINISTRATION, LF, Reserve Energy 2023-01-012023-12-31 C001789 Dillon City (BUTTE), Distribution, Unattended 2023-12-31 C001789 Morgan Stanley Capital Group, Inc. GWA PPW NF MONTANA OATT GLWND2 BRDY 2023-01-012023-12-31 C001789 Ashgrove Transformer Upgrade 2023-01-012023-12-31 C001789 SD 25 Comm Heating 2023-01-012023-12-31 C001789 NorthWestern Energy Solutions, Inc. 2023-01-012023-12-31 C001789 Transalta Energy Marketing (US) Inc. PPW BPAT NF MONTANA OATT YTP BPAT.NWMT 2023-01-012023-12-31 C001789 Three Forks South (BOZEMAN), Distribution, Unattended 2023-01-012023-12-31 C001789 Property Tax, Property Tax, Nebraska, 2022 2022-12-31 C001789 GRANT COUNTY PUD, LF, Reserve Energy 2023-01-012023-12-31 C001789 Ennis City (BOZEMAN), Distribution, Unattended 2023-12-31 C001789 Johnson Lane Bank 1ferc:ElectricUtilityMember 2023-12-31 C001789 Billings Rimrock Auto A (BILLINGS), Transmission, Unattended 2023-12-31 C001789 Neal 2023-12-31 C001789 Other Minor Items (7) - some are amortized over various periods  (Montana) 2022-12-31 C001789 The Energy Authority PPW WAPA SFP MONTANA OATT YTP CROSSOVER 2023-01-012023-12-31 C001789 Tripp Jct. (SD), Transmission, Unattended 2023-01-012023-12-31 C001789 Montana OATT, Attachment O, Formula Rate Protocols and Template, ER21-779-000 2023-01-012023-12-31 C001789 ferc:PropertyTaxMemberferc:ElectricUtilityMember 2023-01-012023-12-31 C001789 EXCHANGES:, , 2023-01-012023-12-31 C001789 Redfield A (SD), Transmission, Unattended 2023-01-012023-12-31 C001789 Holter Wolf Creek (HELENA), Transmission, Unattended 2023-01-012023-12-31 C001789 ferc:ElectricUtilityMemberferc:DistributionPlantMember 2023-01-012023-12-31 C001789 Market Monitoring & Compliance 2023-01-012023-12-31 C001789 ScheduleResearchDevelopmentOrDemonstrationExpendituresAbstract 2023-01-012023-12-31 C001789 ferc:OtherElectricUtilityMember 2022-12-31 C001789 Morgan Stanley Capital Group, Inc. AVA BPAT NF MONTANA OATT AVAT.NWMT BPAT.NWMT 2023-01-012023-12-31 C001789 Western Area Power Administration WAPA PPW NF MONTANA OATT GREATFALLS YTP 2023-01-012023-12-31 C001789 ferc:ElectricPlantInServiceMemberferc:ElectricUtilityMember 2023-12-31 C001789 2188, Holter 2023-01-012023-12-31 C001789 Harlowtown B (BILLINGS), Transmission, Unattended 2023-01-012023-12-31 C001789 Precipitator (BUTTE), Distribution, Unattended 2023-12-31 C001789 Missoula Reserve Street (MISSOULA), Distribution, Unattended 2023-01-012023-12-31 C001789 Use Tax, Sales And Use Tax, Wyoming, 2023 2023-12-31 C001789 Montana Wildfire Mitigation 2023-01-012023-12-31 C001789 Macquarie Energy, LLC NWMT BPAT NF MONTANA OATT TFALLS BPAT.NWMT 2023-01-012023-12-31 C001789 Sibanye-Stillwater Various Stillwater Mining Company FNO Montana OATT As Available Various in Montana 2023-01-012023-12-31 C001789 Transfersferc:ElectricPlantInServiceMemberferc:ElectricUtilityMember 2023-01-012023-12-31 C001789 Transalta Energy Marketing (US) Inc. NWMT AVA NF MONTANA OATT MATL.NWMT AVAT.NWMT 2023-01-012023-12-31 C001789 Billings Central (BILLINGS), Transmission, Unattended 2023-01-012023-12-31 C001789 Morgan Stanley Capital Group, Inc. NWMT NWMT SFP MONTANA OATT CROOKEDFALLS MATL.NWMT 2023-01-012023-12-31 C001789 , , 2023-01-012023-12-31 C001789 ferc:ElectricUtilityMember Ashgrove Transformer Upgrade 2023-01-012023-12-31 C001789 2023-01-012023-12-31 C001789 Miller Crk Rebuildferc:ElectricUtilityMember 2023-01-012023-12-31 C001789 Flow-through Income Taxes (South Dakota) 2023-01-012023-12-31 C001789 Ohlman Substation (SD), Distribution, Unattended 2023-01-012023-12-31 C001789 Aberdeen Siebrecht C (SD), Transmission, Unattended 2023-12-31 C001789 Puget Sound Energy Marketing PPW PPW NF MONTANA OATT MLCK BRDY 2023-01-012023-12-31 C001789 ferc:Quarter3Member South Dakota Operations 2023-01-012023-12-31 C001789 Portland General Electric Company NWMT PPW NF MONTANA OATT COLSTRIP YTP 2023-01-012023-12-31 C001789 Golden Sunlight (BUTTE), Distribution, Unattended 2023-12-31 C001789 Livingston Westside B (BOZEMAN), Distribution, Unattended 2023-12-31 C001789 3% 2023-01-012023-12-31 C001789 Curt Pohl , Vice President, Asset Management & Business Development 2023-01-012023-12-31 C001789 Gross Receipts Tax, Other Taxes, South Dakota, 2023ferc:ElectricUtilityMember 2023-01-012023-12-31 C001789 The Energy Authority WAPA NWMT NF MONTANA OATT CROSSOVER NWMT.SYSTEM 2023-01-012023-12-31 C001789 Highmore Plant A (SD), Transmission, Unattended 2023-12-31 C001789 ferc:SeveranceTaxMember 2023-12-31 C001789 Deferred Compensation (Montana) 2023-12-31 C001789 Portland General Electric Company NWMT AVA NF MONTANA OATT COLSTRIP AVAT.NWMT 2023-01-012023-12-31 C001789 Avista Corporation NWMT BPAT NF MONTANA OATT NWMTIMBALANC BPAT.NWMT 2023-01-012023-12-31 C001789 EELT Tax, Other Taxes, Montana, 2022 2022-12-31 C001789 Transalta Energy Marketing (US) Inc. BPAT PPW NF MONTANA OATT BPAT.NWMT BRDY 2023-01-012023-12-31 C001789 Unamortized Debt Expense (South Dakota) 2023-12-31 C001789 Missoula Reserve Street (MISSOULA), Transmission, Unattended 2023-12-31 C001789 Debt Financing Costs 2023-01-012023-12-31 C001789 CROOKED FALLS-GREAT FALLS ESferc:ElectricUtilityMember 2023-12-31 C001789 First Mortgage Bonds 4.30% (Montana) 2023-12-31 C001789 WMU West Sub (SD), Transmission, Unattended 2023-12-31 C001789 Property Tax, Property Tax, South Dakota, 2022 2023-01-012023-12-31 C001789 Canadian Montana Pipeline Corporation 2023-01-012023-12-31 C001789 ferc:OtherUseTaxMember 2023-12-31 C001789 ferc:FederalInsuranceTaxMember 2023-12-31 C001789 Morgan Stanley Capital Group, Inc. BPAT NWMT NF MONTANA OATT BPAT.NWMT NWMT.SYSTEM 2023-01-012023-12-31 C001789 Mitchell Bridle Acres (SD), Distribution, Unattended 2023-12-31 C001789 Deer Lodge City (BUTTE), Distribution, Unattended 2023-12-31 C001789 Energy Keepers Inc. AVA PPW NF MONTANA OATT AVAT.NWMT ANTE 2023-01-012023-12-31 C001789 Cham. Missouri View (SD), Distribution, Unattended 2023-01-012023-12-31 C001789 Missoula City Sub #1 (MISSOULA), Distribution, Unattended 2023-01-012023-12-31 C001789 Montana Public Service Commission Consumer Counsel Taxes (Montana) - Dockets 2017.9.78 and 2018.10.67 2023-01-012023-12-31 C001789 TOTAL      2023-01-012023-12-31 C001789 Musselshell Wind 1 (NON TIER II QF-1), LU, 2023-01-012023-12-31 C001789 Shell Energy North America AVA NWMT NF MONTANA OATT AVAT.NWMT NWMT.SYSTEM 2023-01-012023-12-31 C001789 Mitchell S. Edgerton (SD), Distribution, Unattended 2023-01-012023-12-31 C001789 Pension Plan Requirement (Montana) 2023-12-31 C001789 Heavy Highway Tax, Other Taxes, South Dakota, 2023 2023-01-012023-12-31 C001789 Boulder Auto (HELENA), Transmission, Unattended 2023-01-012023-12-31 C001789 Canadian-Montana Pipe Line Corporation 2023-12-31 C001789 Livingston Westside C (BOZEMAN), Distribution, Unattended 2023-01-012023-12-31 C001789 NorthWestern Energy Public Services Corporation 2023-01-012023-12-31 C001789 Bob Glanzer Gas 2023-01-012023-12-31 C001789 EDF Trading North America, LLC PPW NWMT NF MONTANA OATT BRDY GTFALLSNWMT 2023-01-012023-12-31 C001789 Federal Unemplyment Tax, Unemployment Tax, Montana, 2023 2023-12-31 C001789 Other Accounts (Specify, details in footnote): 2023-01-012023-12-31 C001789 Great Falls 230Kv - EASTSIDEferc:ElectricUtilityMember 2023-12-31 C001789 Hardin Auto A (BILLINGS), Transmission, Unattended 2023-01-012023-12-31 C001789 Holter U2 Generator Rewind 2023-01-012023-12-31 C001789 Renova Auto (BUTTE), Transmission, Unattended 2023-12-31 C001789 Mahvash Yazdi 2023-01-012023-12-31 C001789 ferc:OtherUtilityOrNonutilityMember OTHER TOTAL 2022-12-31 C001789 Western Area Power Administration PPW WAPA SFP MONTANA OATT YTP GREATFALLS 2023-01-012023-12-31 C001789 Yankton Sacred Heart (SD), Distribution, Unattended 2023-12-31 C001789 Morgan Stanley Capital Group, Inc. WAPA PPW NF MONTANA OATT GREATFALLS BRDY 2023-01-012023-12-31 C001789 Groton Basin Operated (SD), Transmission, Unattended 2023-01-012023-12-31 C001789 Market Monitoring & Compliance 2023-01-012023-03-31 C001789 Missoula Miller Creek A (MISSOULA), Transmission, Unattended 2023-12-31 C001789 Use Tax, Sales And Use Tax, South Dakota, 2023 2023-12-31 C001789 Mercuria Energy America, LLC PPW WAPA NF MONTANA OATT BRDY CROSSOVER 2023-01-012023-12-31 C001789 ferc:OperatingReserveSupplementMember 2023-01-012023-12-31 C001789 Gross Receipts Tax, Other Taxes, South Dakota, 2022 2023-12-31 C001789 Great Divide Solar LLC (NON TIER II SOLAR QF), LU, 2023-01-012023-12-31 C001789 IDAHO POWER COMPANY, LF, Reserve Energy 2023-01-012023-12-31 C001789 Great Falls Eastside (GREAT FALLS), Distribution, Unattended 2023-12-31 C001789 Lake Helena (HELENA), Transmission, Unattended 2023-01-012023-12-31 C001789 ferc:ElectricUtilityMember Federal Income Tax, Income Tax, South Dakota/Nebraska, 2023 2023-01-012023-12-31 C001789 ferc:ElectricUtilityMember Unbilled Revenue 2023-12-31 C001789 Mobile 2 2023-01-012023-12-31 C001789 Huron City B (SD), Distribution, Unattended 2023-01-012023-12-31 C001789 Livingston Northside (BOZEMAN), Distribution, Unattended 2023-01-012023-12-31 C001789 Powerex Corporation NWMT PACE NF MONTANA OATT MATL.NWMT BRDY 2023-01-012023-12-31 C001789 Missoula Industrial Sub (MISSOULA), Distribution, Unattended 2023-12-31 C001789 Other 2022-01-012022-12-31 C001789 Other Miscellaneous 2023-01-012023-12-31 C001789 2022-01-012022-12-31 C001789 South Dakota Detail Footnote 2023-01-012023-12-31 C001789 Columbus East (BILLINGS), Distribution, Unattended 2023-01-012023-12-31 C001789 NorthWestern Energy Solutions - Capital Stockferc:CaptialStockMember 2022-12-31 C001789 Basin Electric Power Cooperative PPW WAPA NF MONTANA OATT YTP GREATFALLS 2023-01-012023-12-31 C001789 MT Lighting 2023-01-012023-12-31 C001789 Macquarie Energy, LLC NWMT BPA NF MONTANA OATT BGI BPAT.NWMT 2023-01-012023-12-31 C001789 Amortization of 2022-01-012022-12-31 C001789 Portland General Electric Company PPW BPAT NF MONTANA OATT BRDY BPAT.NWMT 2023-01-012023-12-31 C001789 First Mortgage Bonds 3.98% (Montana) A 2023-12-31 C001789 Energy Keepers Inc. NWMT BPAT SFP MONTANA OATT COLSTRIP BPAT.NWMT 2023-01-012023-12-31 C001789 Mitchell Jr. High A (SD), Distribution, Unattended 2023-01-012023-12-31 C001789 Montana Public Service Commission, Other Taxes, Montana, 2023 2023-01-012023-12-31 C001789 Dynasty Power, Inc.  , SF, Market-Based Rate 2023-01-012023-12-31 C001789 Idaho Power Company AVA PPW NF MONTANA OATT AVAT.NWMT MLCK 2023-01-012023-12-31 C001789 Morgan Stanley Capital Group, Inc. NWMT BPAT SFP MONTANA OATT MATL.NWMT BPAT.NWMT 2023-01-012023-12-31 C001789 TALEN MONTANA, LLC, LF, Reserve Energy 2023-01-012023-12-31 C001789 PUGET SOUND ENERGY (RESERVE SHARING), LF, Reserve Energy Services 2023-01-012023-12-31 C001789 Missoula Russell Street (MISSOULA), Distribution, Unattended 2023-01-012023-12-31 C001789 Transalta Energy Marketing (US) Inc. BPAT PPW NF MONTANA OATT BPAT.NWMT JEFF 2023-01-012023-12-31 C001789 500 kV Operations - Partner's Share (Montana) 2023-12-31 C001789 Rainbow Electric Marketing Corp. PPW WAPA NF MONTANA OATT BRDY CROSSOVER 2023-01-012023-12-31 C001789 Alkali Creek (BILLINGS), Transmission, Unattended 2023-12-31 C001789 Landers Fork (HELENA), Distribution, Unattended 2023-12-31 C001789 Hydro Invasive Species Tax, Other Taxes, Montana, 2022 2022-12-31 C001789 Projects & Studies Prepaid by Customer (South Dakota) 2023-01-012023-12-31 C001789 Clatskanie Peoples Utility District - Electric (PURCHASED POWER SUPPLY), SF, Market-Based Rate Tariff 2023-01-012023-12-31 C001789 Minor Projects (Less than $250,000 - 18 items)ferc:LandAndRightsMember 2023-01-012023-12-31 C001789 Gross Receipts Tax, Other Taxes, South Dakota, 2022 2023-01-012023-12-31 C001789 Family Protector Plan Future Payments (South Dakota) 2023-01-012023-12-31 C001789 Powerex Corporation NWMT BPAT NF MONTANA OATT MATL.NWMT BPAT.NWMT 2023-01-012023-12-31 C001789 NorthWestern Energy Solutions - Equity in Undistributed Earningsferc:UnappriatedUndistributedSubsidiaryEarningsMember 2023-12-31 C001789 Regulatory Assetsferc:ElectricUtilityMember 2023-01-012023-12-31 C001789 Helena Golf Course Bank #1 (HELENA), Distribution, Unattended 2023-12-31 C001789 FEA Studiesferc:GenerationStudiesMember 2023-01-012023-12-31 C001789 Iberdrola Renewables Inc. BPAT PPW NF MONTANA OATT BPAT.NWMT BRDY 2023-01-012023-12-31 C001789 Clyde Park, Emigrant, Wood H Frame, 556.5 MCM ACSR 2023-01-012023-12-31 C001789 First Mortgage Bonds 4.85% (South Dakota) 2023-12-31 C001789 Powerex Corporation , SF, Market-Based Rate 2023-01-012023-12-31 C001789 Plains (MISSOULA), Distribution, Unattended 2023-12-31 C001789 EDF Trading North America, LLC NWMT NWMT NF MONTANA OATT HARDIN COLSTRIP 2023-01-012023-12-31 C001789 Stanford Auto A (BILLINGS), Transmission, Unattended 2023-12-31 C001789 Other Coyote 2023-01-012023-12-31 C001789 ferc:UnappriatedUndistributedSubsidiaryEarningsMember Risk Partners Assurance, Ltd. - Equity in Undistributed Earnings 2023-01-012023-12-31 C001789 Great Falls Southeast (GREAT FALLS), Distribution, Unattended 2023-01-012023-12-31 C001789 Basin Electric Power Cooperative NWMT WAUW NF MONTANA OATT COLSTRIP GREATFALLS 2023-01-012023-12-31 C001789 Morgan Stanley Capital Group, Inc. GWA BPAT SFP MONTANA OATT GLWND1 BPAT.NWMT 2023-01-012023-12-31 C001789 Transalta Energy Marketing (US) Inc. WAPA AVA NF MONTANA OATT CROSSOVER AVAT.NWMT 2023-01-012023-12-31 C001789 Deferred Compensation (South Dakota) 2023-01-012023-12-31 C001789 Western Area Power Administration WAPA NWMT SFP MONTANA OATT GREATFALLS NWMT.SYSTEM 2023-01-012023-12-31 C001789 Morgan Stanley Capital Group, Inc. NWMT PACE NF MONTANA OATT MATL.NWMT BRDY 2023-01-012023-12-31 C001789 Mill Creek B (BUTTE), Transmission, Unattended 2023-01-012023-12-31 C001789 Montana Tunnels (HELENA), Distribution, Unattended 2023-12-31 C001789 Excess Deferred Income Taxes (South Dakota) 2023-12-31 C001789 Shell Energy North America PPW BPAT NF MONTANA OATT BRDY BPAT.NWMT 2023-01-012023-12-31 C001789 Schroeder (Beethoven Wind) (SD), Transmission, Unattended 2023-01-012023-12-31 C001789 Bozeman Patterson (BOZEMAN), Distribution, Unattended 2023-01-012023-12-31 C001789 Greenfield (NON TIER II QF-1), LU, 2023-01-012023-12-31 C001789 Laurel City (BILLINGS), Distribution, Unattended 2023-12-31 C001789 Delaware Franchise Tax, Franchise Tax, South Dakota, 2023 2023-01-012023-12-31 C001789 Peterson Flats (BUTTE), Transmission, Unattended 2023-01-012023-12-31 C001789 ferc:SalesAndUseTaxMemberferc:ElectricUtilityMember 2023-01-012023-12-31 C001789 Deer Lodge City (BUTTE), Distribution, Unattended 2023-01-012023-12-31 C001789 Big Stone 2023-12-31 C001789 MidAmerican Energy (SOUTH DAKOTA PURCHASES), OS, 2023-01-012023-12-31 C001789 Yankton East Plant B (SD), Transmission, Unattended 2023-01-012023-12-31 C001789 Dynasty Power Inc. NWMT BPAT NF MONTANA OATT MATL.NWMT BPAT.NWMT 2023-01-012023-12-31 C001789 Unbilled Revenues (South Dakota) 2023-12-31 C001789 Hardin City (BILLINGS), Distribution, Unattended 2023-01-012023-12-31 C001789 Highmore ER Interconnect (SD), Transmission, Unattended 2023-12-31 C001789 Beartooth Electric Cooperative, Inc. WAPA & Energy Keepers Inc. Beartooth Electric Cooperative, Inc. FNO Montana OATT Fort Peck & Kerr Various in Montana 2023-01-012023-12-31 C001789 Cycle Power Partners, LLC NWMT PACE NF MONTANA OATT HORSESHOE JEFF 2023-01-012023-12-31 C001789 Kerr, Anaconda B, Wood H Frame, 556.5 MCM ACSR 2023-01-012023-12-31 C001789 SW Freeman (SD), Distribution, Unattended 2023-12-31 C001789 Grand Total 2023-12-31 C001789 Big Stone Plant B (SD), Transmission, Unattended 2023-12-31 C001789 50 Others Under 10,000 KVA (SD), Distribution, Unattended 2023-12-31 C001789 ferc:OtherTaxMember 2023-01-012023-12-31 C001789 ferc:MayMember Montana Operations 2023-01-012023-12-31 C001789 Property Tax - Crow Tribe, Property Tax, Montana, 2023 2023-01-012023-12-31 C001789 Reserves and Accrualsferc:ElectricUtilityMember 2023-01-012023-12-31 C001789 ferc:GasUtilityMember Reserves and Accruals 2023-12-31 C001789 Property Tax, Property Tax, Nebraska, 2023 2023-12-31 C001789 Roundup Auto (BILLINGS), Transmission, Unattended 2023-12-31 C001789 Roosevelt (Tower Falls) 2023-01-012023-12-31 C001789 Morgan Stanley Capital Group, Inc. WAPA BPAT NF MONTANA OATT GREATFALLS BPAT.NWMT 2023-01-012023-12-31 C001789 Shell Energy North America BPAT AVA NF MONTANA OATT BPAT.NWMT AVAT.NWMT 2023-01-012023-12-31 C001789 Darby (MISSOULA), Distribution, Unattended 2023-12-31 C001789 Billings, Great Falls, Wood H Frame, 1272 KCM ACSR 2023-01-012023-12-31 C001789 Huron City B (SD), Distribution, Unattended 2023-12-31 C001789 First Mortgage Bonds 4.30% (South Dakota) 2023-01-012023-12-31 C001789 Huron City A (SD), Distribution, Unattended 2023-12-31 C001789 State Income Tax, State Tax, South Dakota/Nebraska, 2023 2023-12-31 C001789 Huron West Park C (SD), Transmission, Unattended 2023-12-31 C001789 The Energy Authority WAPA AVA NF MONTANA OATT CROSSOVER AVAT.NWMT 2023-01-012023-12-31 C001789 2188, Madison 2023-12-31 C001789 Rainbow Electric Marketing Corp. AVA NWMT NF MONTANA OATT AVAT.NWMT MATL.NWMT 2023-01-012023-12-31 C001789 Coyote, North Dakota (SD), Transmission, Unattended 2023-01-012023-12-31 C001789 Yankton 2023-01-012023-12-31 C001789 Excess Deferred Income Taxes (Montana) 2023-12-31 C001789 Great Falls 230 Switchyard B (GREAT FALLS), Transmission, Unattended 2023-12-31 C001789 Federal Unemplyment Tax, Unemployment Tax, South Dakota, 2023ferc:ElectricUtilityMember 2023-01-012023-12-31 C001789 ferc:GasUtilityMember Excess Tax Depreciation 2023-12-31 C001789 7%ferc:ElectricUtilityMember 2023-01-012023-12-31 C001789 Glasgow Westside (HAVRE), Distribution, Unattended 2023-01-012023-12-31 C001789 Billings Steam Plant Switchyard B (BILLINGS), Transmission, Unattended 2023-12-31 C001789 Rainbow Electric Marketing Corp. NWMT AVA NF MONTANA OATT CANYONFERRY AVAT.NWMT 2023-01-012023-12-31 C001789 Coyote Coal 2023-01-012023-12-31 C001789 Huron SW (SD), Distribution, Unattended 2023-01-012023-12-31 C001789 First Mortgage Bonds 4.11% (Montana) 2023-12-31 C001789 Big Stone, SD, Gary, SD, H-Wood, 1272 MCM 2023-01-012023-12-31 C001789 Roundup Auto (BILLINGS), Transmission, Unattended 2023-01-012023-12-31 C001789 Broadview, Townsend B, St. Tower, 795 KCM ACSR 2023-01-012023-12-31 C001789 Bozeman East Gallatin Auto (BOZEMAN), Distribution, Unattended 2023-12-31 C001789 Missoula Miller Creek Sub site 2023-01-012023-12-31 C001789 Federal Income Tax, Income Tax, Montana, 2023ferc:ElectricUtilityMember 2023-01-012023-12-31 C001789 Morgan Stanley Capital Group, Inc. GWA BPAT NF MONTANA OATT GLWND1 BPAT.NWMT 2023-01-012023-12-31 C001789 ferc:OctoberMember South Dakota Operations 2023-01-012023-12-31 C001789 Shell Energy North America (US), L.P. , SF, Market-Based Rate 2023-01-012023-12-31 C001789 ferc:FebruaryMember Montana Operations 2023-01-012023-12-31 C001789 Risk Partners Assurance, Ltd. 2023-01-012023-12-31 C001789 Capital Leases (miscellaneous) 2023-01-012023-12-31 C001789 Idaho Power Company , SF, Market-Based Rate 2023-01-012023-12-31 C001789 FAS 106 (Montana) - Docket 93.6.24 and Docket 2009.9.129 2022-12-31 C001789 First Mortgage Bonds 4.26% (South Dakota) 2023-12-31 C001789 ferc:JulyMember South Dakota Operations 2023-01-012023-12-31 C001789 Common Stock 2023-01-012023-12-31 C001789 First Mortgage Bonds 3.98% (Montana) B 2023-01-012023-12-31 C001789 Wagner (SD), Distribution, Unattended 2023-12-31 C001789 Pension Requirement (South Dakota) 2022-12-31 C001789 ferc:TwoYearsMemberferc:SulfurDioxideMember 2022-12-31 C001789 PPLM Share of WET Tax (Montana) 2023-12-31 C001789 Basin Electric Power Cooperative PPW PPW NF MONTANA OATT COLSTRIP MLCK 2023-01-012023-12-31 C001789 ferc:PaidInCapitalMember Havre Pipeline Company - Paid in Capital 2022-12-31 C001789 Powerex Corporation BPAT PPW NF MONTANA OATT BPAT.NWMT BRDY 2023-01-012023-12-31 C001789 Bonneville Power Administration BPAT PPW NF MONTANA OATT BPAT.NWMT YTP 2023-01-012023-12-31 C001789 Two Dot Wind Swyd (BILLINGS), Transmission, Unattended 2023-01-012023-12-31 C001789 First Mortgage Bonds 4.15% (South Dakota) 2023-01-012023-12-31 C001789 Town of Philipsburg Town of Philipsburg Town of Philipsburg FNO Montana OATT Philipsburg Substation Philipsburg, MT 2023-01-012023-12-31 C001789 Federal Income Taxes/State Tax Adjustment 2023-01-012023-12-31 C001789 Transalta Energy Marketing (US) Inc. NWMT PACE NF MONTANA OATT MATL.NWMT BRDY 2023-01-012023-12-31 C001789 ferc:GasUtilityMember Regulatory Assets 2022-12-31 C001789 ferc:SteamProductionPlantMemberferc:ElectricUtilityMember 2023-01-012023-12-31 C001789 Hauser U1 Turb-Gen Upgradeferc:ElectricUtilityMember 2023-01-012023-12-31 C001789 Billings Metra Sub Site 2023-01-012023-12-31 C001789 Rainbow Electric Marketing Corp. 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NWMT PACE NF MONTANA OATT HARDIN JEFF 2023-01-012023-12-31 C001789 ScheduleTransmissionOfElectricityByIsoOrRtoAbstract 2023-01-012023-12-31 C001789 Townsend Transmission Sub siteferc:LandAndRightsMember 2023-12-31 C001789 Flow-through Income Taxes (South Dakota) 2023-12-31 C001789 Property Tax - Crow Tribe, Property Tax, Montana, 2021 2023-12-31 C001789 Current Ad Valorem True-Up (South Dakota) - Docket GE98-001 2023-01-012023-12-31 C001789 Kerr Switchyard (MISSOULA), Transmission, Unattended 2023-12-31 C001789 Morgan Stanley Capital Group, Inc. AVA NWMT SFP MONTANA OATT AVAT.NWMT MATL.NWMT 2023-01-012023-12-31 C001789 ferc:DirectPayrollDistributionMember 2023-01-012023-12-31 C001789 Basin Electric Power Cooperative NWMT BPAT NF MONTANA OATT MATL.NWMT BPAT.NWMT 2023-01-012023-12-31 C001789 Property Tax, Property Tax, Iowa, 2021 2023-12-31 C001789 MAG Energy Solutions NWMT PACE NF MONTANA OATT MATL.NWMT BRDY 2023-01-012023-12-31 C001789 Vitol Inc-Electric , SF, Market-Based Rate 2023-01-012023-12-31 C001789 Mobile 4 2023-01-012023-12-31 C001789 Aberdeen #2 2023-12-31 C001789 Gross Receipts Tax, Other Taxes, South Dakota, 2023 2022-12-31 C001789 Pollution Control Revenue Bonds - 3.88% Series, City of Forsyth (Montana) 2023-12-31 C001789 Macquarie Energy, LLC AVA AVA NF MONTANA OATT COLSTRIP AVAT.NWMT 2023-01-012023-12-31 C001789 Platte B (SD), Distribution, Unattended 2023-12-31 C001789 Regulatory Asset/Liability 2023-01-012023-12-31 C001789 Hardin Auto A (BILLINGS), Transmission, Unattended 2023-12-31 C001789 Aberdeen Ethanol (SD), Distribution, Unattended 2023-12-31 C001789 Iberdrola Renewables Inc. 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NWMT BPAT NF MONTANA OATT MATL.NWMT BPAT.NWMT 2023-01-012023-12-31 C001789 Hamilton South Side (MISSOULA), Distribution, Unattended 2023-01-012023-12-31 C001789 Red Lodge Northside (BILLINGS), Distribution, Unattended 2023-12-31 C001789 Hebgen 2023-01-012023-12-31 C001789 Willow Creek Gathering, LLC 2023-01-012023-12-31 C001789 ferc:AfterThreeYearsMemberferc:SulfurDioxideMember 2022-12-31 C001789 Macquarie Energy, LLC AVA PPW NF MONTANA OATT AVAT.NWMT BRDY 2023-01-012023-12-31 C001789 Asset Retirement Obligation (South Dakota) 2023-01-012023-12-31 C001789 CP Energy Marketing (US) Inc. NWMT AVA NF MONTANA OATT MATL.NWMT AVAT.NWMT 2023-01-012023-12-31 C001789 Conrad Auto (GREAT FALLS), Transmission, Unattended 2023-01-012023-12-31 C001789 Cochrane U2 Gen Restack & Rewind 2023-01-012023-12-31 C001789 Big Stone 2023-01-012023-12-31 C001789 EDF Trading North America, LLC NWMT NWMT NF MONTANA OATT COLSTRIP COLSTRIP 2023-01-012023-12-31 C001789 ScheduleNuclearFuelMaterialsAbstract 2023-01-012023-12-31 C001789 Gordon Butte (BILLINGS), Transmission, Unattended 2023-12-31 C001789 Permanent Uncertain Tax Positions (Corporate) 2023-12-31 C001789 Regulatory Assetsferc:ElectricUtilityMember 2023-12-31 C001789 Guzman Energy, LLC BPAT PPW NF MONTANA OATT BPAT.NWMT BRDY 2023-01-012023-12-31 C001789 Property Tax, Property Tax, Iowa, 2022 2023-01-012023-12-31 C001789 ferc:SchedulingSystemControlAndDispatchMember 2023-01-012023-12-31 C001789 ferc:FederalTaxMember 2023-12-31 C001789 Livingston Westside A (BOZEMAN), Transmission, Unattended 2023-01-012023-12-31 C001789 Increases (Decreases) Due to Reductions in Par or Stated Value of Capital Stock 2023-01-012023-12-31 C001789 Bradley Creek (BOZEMAN), Transmission, Unattended 2023-12-31 C001789 First Mortgage Bonds 4.176% (Montana) 2023-12-31 C001789 Property Tax, Property Tax, Montana, 2022 2022-12-31 C001789 Powerex Corporation PPW BPAT NF MONTANA OATT JEFF BPAT.NWMT 2023-01-012023-12-31 C001789 ferc:ElectricUtilityMember Regulatory Asset/Liability 2022-12-31 C001789 MONTANA, , 2023-01-012023-12-31 C001789 Energy Keepers Inc. PPW BPAT SFP MONTANA OATT BRDY BPAT.NWMT 2023-01-012023-12-31 C001789 Morgan Stanley Capital Group, Inc. BPAT AVA NF MONTANA OATT BPAT.NWMT AVAT.NWMT 2023-01-012023-12-31 C001789 Linda G. Sullivan 2023-01-012023-12-31 C001789 Townsend (HELENA), Distribution, Unattended 2023-01-012023-12-31 C001789 Idaho Power Company (PURCHASED POWER SUPPLY), SF, Market-Based Rate Tariff 2023-01-012023-12-31 C001789 Morgan Stanley Capital Group, Inc. BPAT PPW NF MONTANA OATT BPAT.NWMT JEFF 2023-01-012023-12-31 C001789 First Mortgage Bonds 3.11% (Montana) 2023-12-31 C001789 Broadview, Alkali Creek Sub, Wood H Frame, 1272 KCM ACSR 2023-01-012023-12-31 C001789 Bridger City (BILLINGS), Distribution, Unattended 2023-12-31 C001789 Puget Sound Energy Marketing NWMT BPAT NF MONTANA OATT COLSTRIP BPAT.NWMT 2023-01-012023-12-31 C001789 Yankton 2023-12-31 C001789   Pine Creek (TIER II QF), LU, 2023-01-012023-12-31 C001789 Southwest Power Pool (SPP) SPP Various NF SCH 8 Various Various 2023-01-012023-12-31 C001789 SD 95 Public Lighting 2023-01-012023-12-31 C001789 SUPPLY, , 2023-01-012023-12-31 C001789 ferc:GasUtilityMember Regulatory Assets 2023-01-012023-12-31 C001789 ferc:GenerationStudiesMember SIS Studies 2023-01-012023-12-31 C001789 ferc:GasUtilityMember Compensation Accruals 2023-12-31 C001789 Aurora Wind (SOUTH DAKOTA PURCHASES), LU, 2023-01-012023-12-31 C001789 Rainbow Electric Marketing Corp. WAPA BPAT NF MONTANA OATT CROSSOVER BPAT.NWMT 2023-01-012023-12-31 C001789 Montana Operationsferc:JulyMember 2023-01-012023-12-31 C001789 Western Area Power Administration NWMT WAPA NF MONTANA OATT CANYONFERRY CROSSOVER 2023-01-012023-12-31 C001789 ferc:GasUtilityMember Reserves and Accruals 2022-12-31 C001789 Bozeman Jackrabbit Auto (BOZEMAN), Transmission, Unattended 2023-12-31 C001789 Mobile 8 2023-12-31 C001789 Alpena (SD), Distribution, Unattended 2023-12-31 C001789 Western Area Power Administration WAPA WAPA NF MONTANA OATT GREATFALLS CROSSOVER 2023-01-012023-12-31 C001789 Contributions & Advances for Construction 2023-01-012023-12-31 C001789 Guzman Energy, LLC PPW WAPA NF MONTANA OATT YTP GREATFALLS 2023-01-012023-12-31 C001789 NorthWestern Services, LLC 2023-01-012023-12-31 C001789 Coyote 2023-12-31 C001789 ferc:CaptialStockMember NorthWestern Public Service - Capital Stock 2023-01-012023-12-31 C001789 Permanent Uncertain Tax Positions (Corporate) 2023-01-012023-12-31 C001789 Redfield D (SD), Transmission, Unattended 2023-12-31 C001789 The Energy Authority WAPA BPAT SFP MONTANA OATT CROSSOVER BPAT.NWMT 2023-01-012023-12-31 C001789 Macquarie Energy, LLC PPW PPW NF MONTANA OATT YTP BRDY 2023-01-012023-12-31 C001789 Seattle City Light (PURCHASED POWER SUPPLY), SF, Market-Based Rate Tariff 2023-01-012023-12-31 C001789 Shell Energy North America WAPA BPAT NF MONTANA OATT CROSSOVER BPAT.NWMT 2023-01-012023-12-31 C001789 Billings Conoco (BILLINGS), Distribution, Unattended 2023-01-012023-12-31 iso4217:USD utr:bbl utr:Btu iso4217:USD utr:MMBTU utr:T iso4217:USD utr:T utr:mi utr:MW utr:MMBTU xbrli:pure xbrli:shares utr:MWh iso4217:USD utr:bbl utr:Btu utr:kWh utr:kWh iso4217:USD utr:kWh iso4217:USD xbrli:shares iso4217:USD utr:MW utr:MVA iso4217:USD utr:kW utr:kV
THIS FILING IS
Item 1:
An Initial (Original) Submission
OR
Resubmission No.

FERC FINANCIAL REPORT
FERC FORM No. 1: Annual Report of
Major Electric Utilities, Licensees
and Others and Supplemental
Form 3-Q: Quarterly Financial Report

These reports are mandatory under the Federal Power Act, Sections 3, 4(a), 304 and 309, and 18 CFR 141.1 and 141.400. Failure to report may result in criminal fines, civil penalties and other sanctions as provided by law. The Federal Energy Regulatory Commission does not consider these reports to be of confidential nature
Exact Legal Name of Respondent (Company)

NorthWestern Corporation
Year/Period of Report

End of:
2023
/
Q4


INSTRUCTIONS FOR FILING FERC FORM NOS. 1 and 3-Q

GENERAL INFORMATION

  1. Purpose

    FERC Form No. 1 (FERC Form 1) is an annual regulatory requirement for Major electric utilities, licensees and others (18 C.F.R. § 141.1). FERC Form No. 3-Q ( FERC Form 3-Q) is a quarterly regulatory requirement which supplements the annual financial reporting requirement (18 C.F.R. § 141.400). These reports are designed to collect financial and operational information from electric utilities, licensees and others subject to the jurisdiction of the Federal Energy Regulatory Commission. These reports are also considered to be non-confidential public use forms.
  2. Who Must Submit

    Each Major electric utility, licensee, or other, as classified in the Commission’s Uniform System of Accounts Prescribed for Public Utilities, Licensees, and Others Subject To the Provisions of The Federal Power Act (18 C.F.R. Part 101), must submit FERC Form 1 (18 C.F.R. § 141.1), and FERC Form 3-Q (18 C.F.R. § 141.400).

    Note: Major means having, in each of the three previous calendar years, sales or transmission service that exceeds one of the following:
    1. one million megawatt hours of total annual sales,
    2. 100 megawatt hours of annual sales for resale,
    3. 500 megawatt hours of annual power exchanges delivered, or
    4. 500 megawatt hours of annual wheeling for others (deliveries plus losses).
  3. What and Where to Submit

    1. Submit FERC Form Nos. 1 and 3-Q electronically through the eCollection portal at https://eCollection.ferc.gov, and according to the specifications in the Form 1 and 3-Q taxonomies.
    2. The Corporate Officer Certification must be submitted electronically as part of the FERC Forms 1 and 3-Q filings.
    3. Submit immediately upon publication, by either eFiling or mail, two (2) copies to the Secretary of the Commission, the latest Annual Report to Stockholders. Unless eFiling the Annual Report to Stockholders, mail the stockholders report to the Secretary of the Commission at:
      Secretary
      Federal Energy Regulatory Commission 888 First Street, NE
      Washington, DC 20426
    4. For the CPA Certification Statement, submit within 30 days after filing the FERC Form 1, a letter or report (not applicable to filers classified as Class C or Class D prior to January 1, 1984). The CPA Certification Statement can be either eFiled or mailed to the Secretary of the Commission at the address above.

      The CPA Certification Statement should:
      1. Attest to the conformity, in all material aspects, of the below listed (schedules and pages) with the Commission's applicable Uniform System of Accounts (including applicable notes relating thereto and the Chief Accountant's published accounting releases), and
      2. Be signed by independent certified public accountants or an independent licensed public accountant certified or licensed by a regulatory authority of a State or other political subdivision of the U. S. (See 18 C.F.R. §§ 41.10-41.12 for specific qualifications.)

        Schedules
        Pages
        Comparative Balance Sheet 110-113
        Statement of Income 114-117
        Statement of Retained Earnings 118-119
        Statement of Cash Flows 120-121
        Notes to Financial Statements 122-123
    5. The following format must be used for the CPA Certification Statement unless unusual circumstances or conditions, explained in the letter or report, demand that it be varied. Insert parenthetical phrases only when exceptions are reported.

      “In connection with our regular examination of the financial statements of [COMPANY NAME] for the year ended on which we have reported separately under date of [DATE], we have also reviewed schedules [NAME OF SCHEDULES] of FERC Form No. 1 for the year filed with the Federal Energy Regulatory Commission, for conformity in all material respects with the requirements of the Federal Energy Regulatory Commission as set forth in its applicable Uniform System of Accounts and published accounting releases. Our review for this purpose included such tests of the accounting records and such other auditing procedures as we considered necessary in the circumstances.

      Based on our review, in our opinion the accompanying schedules identified in the preceding paragraph (except as noted below) conform in all material respects with the accounting requirements of the Federal Energy Regulatory Commission as set forth in its applicable Uniform System of Accounts and published accounting releases.” The letter or report must state which, if any, of the pages above do not conform to the Commission’s requirements. Describe the discrepancies that exist.
    6. Filers are encouraged to file their Annual Report to Stockholders, and the CPA Certification Statement using eFiling. Further instructions are found on the Commission’s website at https://www.ferc.gov/ferc-online/ferc-online/frequently-asked-questions-faqs-efilingferc-online.
    7. Federal, State, and Local Governments and other authorized users may obtain additional blank copies of FERC Form 1 and 3-Q free of charge from https://www.ferc.gov/general-information-0/electric-industry-forms.
  4. When to Submit

    FERC Forms 1 and 3-Q must be filed by the following schedule:

    1. FERC Form 1 for each year ending December 31 must be filed by April 18th of the following year (18 CFR § 141.1), and
    2. FERC Form 3-Q for each calendar quarter must be filed within 60 days after the reporting quarter (18 C.F.R. § 141.400).
  5. Where to Send Comments on Public Reporting Burden.

    The public reporting burden for the FERC Form 1 collection of information is estimated to average 1,168 hours per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data-needed, and completing and reviewing the collection of information. The public reporting burden for the FERC Form 3-Q collection of information is estimated to average 168 hours per response.

    Send comments regarding these burden estimates or any aspect of these collections of information, including suggestions for reducing burden, to the Federal Energy Regulatory Commission, 888 First Street NE, Washington, DC 20426 (Attention: Information Clearance Officer); and to the Office of Information and Regulatory Affairs, Office of Management and Budget, Washington, DC 20503 (Attention: Desk Officer for the Federal Energy Regulatory Commission). No person shall be subject to any penalty if any collection of information does not display a valid control number (44 U.S.C. § 3512 (a)).

GENERAL INSTRUCTIONS

  1. Prepare this report in conformity with the Uniform System of Accounts (18 CFR Part 101) (USofA). Interpret all accounting words and phrases in accordance with the USofA.
  2. Enter in whole numbers (dollars or MWH) only, except where otherwise noted. (Enter cents for averages and figures per unit where cents are important. The truncating of cents is allowed except on the four basic financial statements where rounding is required.) The amounts shown on all supporting pages must agree with the amounts entered on the statements that they support. When applying thresholds to determine significance for reporting purposes, use for balance sheet accounts the balances at the end of the current reporting period, and use for statement of income accounts the current year's year to date amounts.
  3. Complete each question fully and accurately, even if it has been answered in a previous report. Enter the word "None" where it truly and completely states the fact.
  4. For any page(s) that is not applicable to the respondent, omit the page(s) and enter "NA," "NONE," or "Not Applicable" in column (d) on the List of Schedules, pages 2 and 3.
  5. Enter the month, day, and year for all dates. Use customary abbreviations. The "Date of Report" included in the header of each page is to be completed only for resubmissions (see VII. below).
  6. Generally, except for certain schedules, all numbers, whether they are expected to be debits or credits, must be reported as positive. Numbers having a sign that is different from the expected sign must be reported by enclosing the numbers in parentheses.
  7. For any resubmissions, please explain the reason for the resubmission in a footnote to the data field.
  8. Do not make references to reports of previous periods/years or to other reports in lieu of required entries, except as specifically authorized.
  9. Wherever (schedule) pages refer to figures from a previous period/year, the figures reported must be based upon those shown by the report of the previous period/year, or an appropriate explanation given as to why the different figures were used.
  10. Schedule specific instructions are found in the applicable taxonomy and on the applicable blank rendered form.
Definitions for statistical classifications used for completing schedules for transmission system reporting are as follows:

FNS - Firm Network Transmission Service for Self. "Firm" means service that can not be interrupted for economic reasons and is intended to remain reliable even under adverse conditions. "Network Service" is Network Transmission Service as described in Order No. 888 and the Open Access Transmission Tariff. "Self" means the respondent.

FNO - Firm Network Service for Others. "Firm" means that service cannot be interrupted for economic reasons and is intended to remain reliable even under adverse conditions. "Network Service" is Network Transmission Service as described in Order No. 888 and the Open Access Transmission Tariff.

LFP - for Long-Term Firm Point-to-Point Transmission Reservations. "Long-Term" means one year or longer and” firm" means that service cannot be interrupted for economic reasons and is intended to remain reliable even under adverse conditions. "Point-to-Point Transmission Reservations" are described in Order No. 888 and the Open Access Transmission Tariff. For all transactions identified as LFP, provide in a footnote the termination date of the contract defined as the earliest date either buyer or seller can unilaterally cancel the contract.

OLF - Other Long-Term Firm Transmission Service. Report service provided under contracts which do not conform to the terms of the Open Access Transmission Tariff. "Long-Term" means one year or longer and “firm” means that service cannot be interrupted for economic reasons and is intended to remain reliable even under adverse conditions. For all transactions identified as OLF, provide in a footnote the termination date of the contract defined as the earliest date either buyer or seller can unilaterally get out of the contract.

SFP - Short-Term Firm Point-to-Point Transmission Reservations. Use this classification for all firm point-to-point transmission reservations, where the duration of each period of reservation is less than one-year.

NF - Non-Firm Transmission Service, where firm means that service cannot be interrupted for economic reasons and is intended to remain reliable even under adverse conditions.

OS - Other Transmission Service. Use this classification only for those services which can not be placed in the above-mentioned classifications, such as all other service regardless of the length of the contract and service FERC Form. Describe the type of service in a footnote for each entry.

AD - Out-of-Period Adjustments. Use this code for any accounting adjustments or "true-ups" for service provided in prior reporting periods. Provide an explanation in a footnote for each adjustment.

DEFINITIONS
  1. Commission Authorization (Comm. Auth.) -- The authorization of the Federal Energy Regulatory Commission, or any other Commission. Name the commission whose authorization was obtained and give date of the authorization.
  2. Respondent -- The person, corporation, licensee, agency, authority, or other Legal entity or instrumentality in whose behalf the report is made.

EXCERPTS FROM THE LAW

Federal Power Act, 16 U.S.C. § 791a-825r

Sec. 3. The words defined in this section shall have the following meanings for purposes of this Act, to with:

  1. ’Corporation' means any corporation, joint-stock company, partnership, association, business trust, organized group of persons, whether incorporated or not, or a receiver or receivers, trustee or trustees of any of the foregoing. It shall not include 'municipalities, as hereinafter defined;
  2. 'Person' means an individual or a corporation;
  3. 'Licensee, means any person, State, or municipality Licensed under the provisions of section 4 of this Act, and any assignee or successor in interest thereof;
  1. 'municipality means a city, county, irrigation district, drainage district, or other political subdivision or agency of a State competent under the Laws thereof to carry and the business of developing, transmitting, unitizing, or distributing power; ......
  1. "project' means. a complete unit of improvement or development, consisting of a power house, all water conduits, all dams and appurtenant works and structures (including navigation structures) which are a part of said unit, and all storage, diverting, or fore bay reservoirs directly connected therewith, the primary line or lines transmitting power there from to the point of junction with the distribution system or with the interconnected primary transmission system, all miscellaneous structures used and useful in connection with said unit or any part thereof, and all water rights, rights-of-way, ditches, dams, reservoirs, Lands, or interest in Lands the use and occupancy of which are necessary or appropriate in the maintenance and operation of such unit;

"Sec. 4. The Commission is hereby authorized and empowered
  1. 'To make investigations and to collect and record data concerning the utilization of the water 'resources of any region to be developed, the water-power industry and its relation to other industries and to interstate or foreign commerce, and concerning the location, capacity, development costs, and relation to markets of power sites; ... to the extent the Commission may deem necessary or useful for the purposes of this Act."

"Sec. 304.
  1. Every Licensee and every public utility shall file with the Commission such annual and other periodic or special* reports as the Commission may by rules and regulations or other prescribe as necessary or appropriate to assist the Commission in the proper administration of this Act. The Commission may prescribe the manner and FERC Form in which such reports shall be made, and require from such persons specific answers to all questions upon which the Commission may need information. The Commission may require that such reports shall include, among other things, full information as to assets and Liabilities, capitalization, net investment, and reduction thereof, gross receipts, interest due and paid, depreciation, and other reserves, cost of project and other facilities, cost of maintenance and operation of the project and other facilities, cost of renewals and replacement of the project works and other facilities, depreciation, generation, transmission, distribution, delivery, use, and sale of electric energy. The Commission may require any such person to make adequate provision for currently determining such costs and other facts. Such reports shall be made under oath unless the Commission otherwise specifies*.10
"Sec. 309.
  1. The Commission shall have power to perform any and all acts, and to prescribe, issue, make, and rescind such orders, rules and regulations as it may find necessary or appropriate to carry out the provisions of this Act. Among other things, such rules and regulations may define accounting, technical, and trade terms used in this Act; and may prescribe the FERC Form or FERC Forms of all statements, declarations, applications, and reports to be filed with the Commission, the information which they shall contain, and the time within which they shall be field..."

GENERAL PENALTIES

The Commission may assess up to $1 million per day per violation of its rules and regulations. See FPA § 316(a) (2005), 16 U.S.C. § 825o(a).


FERC FORM NO.
1

REPORT OF MAJOR ELECTRIC UTILITIES, LICENSEES AND OTHER
IDENTIFICATION
01 Exact Legal Name of Respondent

NorthWestern Corporation
02 Year/ Period of Report


End of:
2023
/
Q4
03 Previous Name and Date of Change (If name changed during year)

/
04 Address of Principal Office at End of Period (Street, City, State, Zip Code)

3010 West 69th Street Sioux Falls, SD 57108
05 Name of Contact Person

Evan VerWey
06 Title of Contact Person

Manager of Financial Reporting
07 Address of Contact Person (Street, City, State, Zip Code)

3010 West 69th Street Sioux Falls, SD 57108
08 Telephone of Contact Person, Including Area Code

(605) 978-2906
09 This Report is An Original / A Resubmission

(1)
An Original

(2)
A Resubmission
10 Date of Report (Mo, Da, Yr)

12/31/2023
Annual Corporate Officer Certification
The undersigned officer certifies that:

I have examined this report and to the best of my knowledge, information, and belief all statements of fact contained in this report are correct statements of the business affairs of the respondent and the financial statements, and other financial information contained in this report, conform in all material respects to the Uniform System of Accounts.

01 Name

Jeff Berzina
02 Title

Controller
03 Signature

Jeff Berzina
04 Date Signed (Mo, Da, Yr)

02/28/2023
Title 18, U.S.C. 1001 makes it a crime for any person to knowingly and willingly to make to any Agency or Department of the United States any false, fictitious or fraudulent statements as to any matter within its jurisdiction.


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
LIST OF SCHEDULES (Electric Utility)

Enter in column (c) the terms "none," "not applicable," or "NA," as appropriate, where no information or amounts have been reported for certain pages. Omit pages where the respondents are "none," "not applicable," or "NA".

Line No.
Title of Schedule
(a)
Reference Page No.
(b)
Remarks
(c)
ScheduleIdentificationAbstract
Identification
1
ScheduleListOfSchedulesAbstract
List of Schedules
2
1
ScheduleGeneralInformationAbstract
General Information
101
2
ScheduleControlOverRespondentAbstract
Control Over Respondent
102
3
ScheduleCorporationsControlledByRespondentAbstract
Corporations Controlled by Respondent
103
4
ScheduleOfficersAbstract
Officers
104
5
ScheduleDirectorsAbstract
Directors
105
6
ScheduleInformationOnFormulaRatesAbstract
Information on Formula Rates
106
7
ScheduleImportantChangesDuringTheQuarterYearAbstract
Important Changes During the Year
108
8
ScheduleComparativeBalanceSheetAbstract
Comparative Balance Sheet
110
9
ScheduleStatementOfIncomeAbstract
Statement of Income for the Year
114
10
ScheduleRetainedEarningsAbstract
Statement of Retained Earnings for the Year
118
12
ScheduleStatementOfCashFlowsAbstract
Statement of Cash Flows
120
12
ScheduleNotesToFinancialStatementsAbstract
Notes to Financial Statements
122
13
ScheduleStatementOfAccumulatedOtherComprehensiveIncomeAndHedgingActivitiesAbstract
Statement of Accum Other Comp Income, Comp Income, and Hedging Activities
122a
14
ScheduleSummaryOfUtilityPlantAndAccumulatedProvisionsForDepreciationAmortizationAndDepletionAbstract
Summary of Utility Plant & Accumulated Provisions for Dep, Amort & Dep
200
15
ScheduleNuclearFuelMaterialsAbstract
Nuclear Fuel Materials
202
Not Applicable
16
ScheduleElectricPlantInServiceAbstract
Electric Plant in Service
204
17
ScheduleElectricPropertyLeasedToOthersAbstract
Electric Plant Leased to Others
213
Not Applicable
18
ScheduleElectricPlantHeldForFutureUseAbstract
Electric Plant Held for Future Use
214
19
ScheduleConstructionWorkInProgressElectricAbstract
Construction Work in Progress-Electric
216
20
ScheduleAccumulatedProvisionForDepreciationOfElectricUtilityPlantAbstract
Accumulated Provision for Depreciation of Electric Utility Plant
219
21
ScheduleInvestmentsInSubsidiaryCompaniesAbstract
Investment of Subsidiary Companies
224
22
ScheduleMaterialsAndSuppliesAbstract
Materials and Supplies
227
23
ScheduleAllowanceInventoryAbstract
Allowances
228
24
ScheduleExtraordinaryPropertyLossesAbstract
Extraordinary Property Losses
230a
Not Applicable
25
ScheduleUnrecoveredPlantAndRegulatoryStudyCostsAbstract
Unrecovered Plant and Regulatory Study Costs
230b
Not Applicable
26
ScheduleTransmissionServiceAndGenerationInterconnectionStudyCostsAbstract
Transmission Service and Generation Interconnection Study Costs
231
27
ScheduleOtherRegulatoryAssetsAbstract
Other Regulatory Assets
232
28
ScheduleMiscellaneousDeferredDebitsAbstract
Miscellaneous Deferred Debits
233
29
ScheduleAccumulatedDeferredIncomeTaxesAbstract
Accumulated Deferred Income Taxes
234
30
ScheduleCapitalStockAbstract
Capital Stock
250
31
ScheduleOtherPaidInCapitalAbstract
Other Paid-in Capital
253
32
ScheduleCapitalStockExpenseAbstract
Capital Stock Expense
254b
Not Applicable
33
ScheduleLongTermDebtAbstract
Long-Term Debt
256
34
ScheduleReconciliationOfReportedNetIncomeWithTaxableIncomeForFederalIncomeTaxesAbstract
Reconciliation of Reported Net Income with Taxable Inc for Fed Inc Tax
261
35
ScheduleTaxesAccruedPrepaidAndChargedDuringYearDistributionOfTaxesChargedAbstract
Taxes Accrued, Prepaid and Charged During the Year
262
36
ScheduleAccumulatedDeferredInvestmentTaxCreditsAbstract
Accumulated Deferred Investment Tax Credits
266
37
ScheduleOtherDeferredCreditsAbstract
Other Deferred Credits
269
38
ScheduleAccumulatedDeferredIncomeTaxesAcceleratedAmortizationPropertyAbstract
Accumulated Deferred Income Taxes-Accelerated Amortization Property
272
Not Applicable
39
ScheduleAccumulatedDeferredIncomeTaxesOtherPropertyAbstract
Accumulated Deferred Income Taxes-Other Property
274
40
ScheduleAccumulatedDeferredIncomeTaxesOtherAbstract
Accumulated Deferred Income Taxes-Other
276
41
ScheduleOtherRegulatoryLiabilitiesAbstract
Other Regulatory Liabilities
278
42
ScheduleElectricOperatingRevenuesAbstract
Electric Operating Revenues
300
43
ScheduleRegionalTransmissionServiceRevenuesAbstract
Regional Transmission Service Revenues (Account 457.1)
302
Not Applicable
44
ScheduleSalesOfElectricityByRateSchedulesAbstract
Sales of Electricity by Rate Schedules
304
45
ScheduleSalesForResaleAbstract
Sales for Resale
310
46
ScheduleElectricOperationsAndMaintenanceExpensesAbstract
Electric Operation and Maintenance Expenses
320
47
SchedulePurchasedPowerAbstract
Purchased Power
326
48
ScheduleTransmissionOfElectricityForOthersAbstract
Transmission of Electricity for Others
328
49
ScheduleTransmissionOfElectricityByIsoOrRtoAbstract
Transmission of Electricity by ISO/RTOs
331
Not Applicable
50
ScheduleTransmissionOfElectricityByOthersAbstract
Transmission of Electricity by Others
332
51
ScheduleMiscellaneousGeneralExpensesAbstract
Miscellaneous General Expenses-Electric
335
52
ScheduleDepreciationDepletionAndAmortizationAbstract
Depreciation and Amortization of Electric Plant (Account 403, 404, 405)
336
53
ScheduleRegulatoryCommissionExpensesAbstract
Regulatory Commission Expenses
350
54
ScheduleResearchDevelopmentOrDemonstrationExpendituresAbstract
Research, Development and Demonstration Activities
352
Not Applicable
55
ScheduleDistributionOfSalariesAndWagesAbstract
Distribution of Salaries and Wages
354
56
ScheduleCommonUtilityPlantAndExpensesAbstract
Common Utility Plant and Expenses
356
57
ScheduleAmountsIncludedInIsoOrRtoSettlementAbstract
Amounts included in ISO/RTO Settlement Statements
397
58
SchedulePurchasesSalesOfAncillaryServicesAbstract
Purchase and Sale of Ancillary Services
398
59
ScheduleMonthlyTransmissionSystemPeakLoadAbstract
Monthly Transmission System Peak Load
400
60
ScheduleMonthlyIsoOrRtoTransmissionSystemPeakLoadAbstract
Monthly ISO/RTO Transmission System Peak Load
400a
61
ScheduleElectricEnergyAccountAbstract
Electric Energy Account
401a
62
ScheduleMonthlyPeakAndOutputAbstract
Monthly Peaks and Output
401b
63
ScheduleSteamElectricGeneratingPlantStatisticsAbstract
Steam Electric Generating Plant Statistics
402
64
ScheduleHydroelectricGeneratingPlantStatisticsAbstract
Hydroelectric Generating Plant Statistics
406
65
SchedulePumpedStorageGeneratingPlantStatisticsAbstract
Pumped Storage Generating Plant Statistics
408
Not Applicable
66
ScheduleGeneratingPlantStatisticsAbstract
Generating Plant Statistics Pages
410
66.1
ScheduleEnergyStorageOperationsLargePlantsAbstract
Energy Storage Operations (Large Plants)
414
66.2
ScheduleEnergyStorageOperationsSmallPlantsAbstract
Energy Storage Operations (Small Plants)
419
67
ScheduleTransmissionLineStatisticsAbstract
Transmission Line Statistics Pages
422
68
ScheduleTransmissionLinesAddedAbstract
Transmission Lines Added During Year
424
None
69
ScheduleSubstationsAbstract
Substations
426
70
ScheduleTransactionsWithAssociatedAffiliatedCompaniesAbstract
Transactions with Associated (Affiliated) Companies
429
71
FootnoteDataAbstract
Footnote Data
450
StockholdersReportsAbstract
Stockholders' Reports (check appropriate box)
Stockholders' Reports Check appropriate box:

Two copies will be submitted

No annual report to stockholders is prepared


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
GENERAL INFORMATION
1. Provide name and title of officer having custody of the general corporate books of account and address of office where the general corporate books are kept, and address of office where any other corporate books of account are kept, if different from that where the general corporate books are kept.

Jeff B. Berzina

Controller

3010 West 69th Street Sioux Falls, SD 57108
2. Provide the name of the State under the laws of which respondent is incorporated, and date of incorporation. If incorporated under a special law, give reference to such law. If not incorporated, state that fact and give the type of organization and the date organized.

State of Incorporation:
DE

Date of Incorporation:
1923-11-27

Incorporated Under Special Law:

3. If at any time during the year the property of respondent was held by a receiver or trustee, give (a) name of receiver or trustee, (b) date such receiver or trustee took possession, (c) the authority by which the receivership or trusteeship was created, and (d) date when possession by receiver or trustee ceased.

(a) Name of Receiver or Trustee Holding Property of the Respondent:

(b) Date Receiver took Possession of Respondent Property:

(c) Authority by which the Receivership or Trusteeship was created:

(d) Date when possession by receiver or trustee ceased:
4. State the classes or utility and other services furnished by respondent during the year in each State in which the respondent operated.

Electric and Natural Gas Utility in Montana and South Dakota; Electric Utility in Wyoming (Yellowstone National Park); Natural Gas Utility in Nebraska; and Propane in Montana
5. Have you engaged as the principal accountant to audit your financial statements an accountant who is not the principal accountant for your previous year's certified financial statements?
(1)
Yes

(2)
No


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
CONTROL OVER RESPONDENT
1. If any corporation, business trust, or similar organization or a combination of such organizations jointly held control over the respondent at the end of the year, state name of controlling corporation or organization, manner in which control was held, and extent of control. If control was in a holding company organization, show the chain of ownership or control to the main parent company or organization. If control was held by a trustee(s), state name of trustee(s), name of beneficiary or beneficiaries for whom trust was maintained, and purpose of the trust.
Respondent is a wholly-owned, direct subsidiary of NorthWestern Energy Group, Inc. At December 31, 2023, NorthWestern Energy Group, Inc. owned 100% of the common stock of Respondent.


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
CORPORATIONS CONTROLLED BY RESPONDENT
  1. Report below the names of all corporations, business trusts, and similar organizations, controlled directly or indirectly by respondent at any time during the year. If control ceased prior to end of year, give particulars (details) in a footnote.
  2. If control was by other means than a direct holding of voting rights, state in a footnote the manner in which control was held, naming any intermediaries involved.
  3. If control was held jointly with one or more other interests, state the fact in a footnote and name the other interests.
Definitions
  1. See the Uniform System of Accounts for a definition of control.
  2. Direct control is that which is exercised without interposition of an intermediary.
  3. Indirect control is that which is exercised by the interposition of an intermediary which exercises direct control.
  4. Joint control is that in which neither interest can effectively control or direct action without the consent of the other, as where the voting control is equally divided between two holders, or each party holds a veto power over the other. Joint control may exist by mutual agreement or understanding between two or more parties who together have control within the meaning of the definition of control in the Uniform System of Accounts, regardless of the relative voting rights of each party.
Line No.
NameOfCompanyControlledByRespondent
Name of Company Controlled
(a)
CompanyControlledByRespondentKindOfBusinessDescription
Kind of Business
(b)
VotingStockOwnedByRespondentPercentage
Percent Voting Stock Owned
(c)
FootnoteReferences
Footnote Ref.
(d)
1
Direct Subsidiaries:
2
Canadian-Montana Pipe Line Corporation
Owns natural gas pipeline
100
3
Clarkfork and Blackfoot, LLC
Owned a former hydro facility in Montana
100
4
NorthWestern Services, LLC
Non-regulated natural gas marketing in SD/NE
100
5
Risk Partners Assurance, Ltd.
Captive insurance company
100
6
Lodge Creek Pipelines, LLC
Natural gas gathering system
100
7
Willow Creek Gathering, LLC
Natural gas gathering system
100
8
Havre Pipeline Company, LLC
Natural gas transmission and gathering system
96
9
NorthWestern Energy Solutions, Inc.
Non-regulated customer services
100
10
NorthWestern Energy Public Services Corporation
(a)
Provides electricity and natural gas to South Dakota and Nebraska
100


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
FOOTNOTE DATA

(a) Concept: CompanyControlledByRespondentKindOfBusinessDescription
This statement is as of January 1, 2024. This legal entity was created in 2023 as part of our holding company reorganization and did not hold any assets or liabilities as of December 31, 2023. See page 108 section 2 for further information detailing the effectuation of our holding company structure as of January 1, 2024.

Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
OFFICERS
  1. Report below the name, title and salary for each executive officer whose salary is $50,000 or more. An "executive officer" of a respondent includes its president, secretary, treasurer, and vice president in charge of a principal business unit, division or function (such as sales, administration or finance), and any other person who performs similar policy making functions.
  2. If a change was made during the year in the incumbent of any position, show name and total remuneration of the previous incumbent, and the date the change in incumbency was made.
Line No.
OfficerTitle
Title
(a)
OfficerName
Name of Officer
(b)
OfficerSalary
Salary for Year
(c)
DateOfficerIncumbencyStarted
Date Started in Period
(d)
DateOfficerIncumbencyEnded
Date Ended in Period
(e)
1
President and Chief Executive Officer
Brian Bird
794,519
2023-01-01
2
Vice President, Chief Financial Officer
Crystal Lail
457,716
3
Vice President, General Counsel and Federal Government Affairs
Shannon Heim
347,369
2023-01-01
4
Vice President, Asset Management & Business Development
Bleau Lafave
231,687
2023-06-16
5
Vice President, Customer Care, Communications, and Human Resources
Bobbi Schroeppel
325,187
6
Vice President, Regulatory Affairs
Cyndee Fang
244,151
2023-01-01
7
Vice President, Distribution
Jason Merkel
255,008
8
Vice President, Technology
Jeanne Vold
266,909
9
Vice President, Supply and Montana Government Affairs
John Hines
326,553
10
Vice President, Transmission
Michael Cashell
324,917
11
Vice President, Asset Management & Business Development
Curt Pohl
158,770
2023-06-16


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
DIRECTORS
  1. Report below the information called for concerning each director of the respondent who held office at any time during the year. Include in column (a), name and abbreviated titles of the directors who are officers of the respondent.
  2. Provide the principle place of business in column (b), designate members of the Executive Committee in column (c), and the Chairman of the Executive Committee in column (d).
Line No.
NameAndTitleOfDirector
Name (and Title) of Director
(a)
PrincipalBusinessAddress
Principal Business Address
(b)
MemberOfTheExecutiveCommittee
Member of the Executive Committee
(c)
ChairmanOfTheExecutiveCommittee
Chairman of the Executive Committee
(d)
1
Dana J. Dykhouse
Sioux Falls, South Dakota
false
false
2
Anthony T. Clark
Ashburn, Virginia
false
false
3
Jan R. Horsfall
Colorado Springs, Colorado
false
false
4
Britt E. Ide
Bozeman, Montana
false
false
5
Linda G. Sullivan
Moneta, Virginia
false
false
6
Mahvash Yazdi
Rancho Palos Verdes, California
false
false
7
Jeffrey W. Yingling
Kneilworth, Illinois
false
false
8
Kent T. Larson
Shoreview, Minnesota
false
false
9
Sherina Edwards
Chicago, Illinois
false
false
10
Brian Bird (President and CEO)
Sioux Falls, South Dakota
false
false
11
Crystal Lail (VP and CFO)
Sioux Falls, South Dakota
false
false
12
Shannon Heim (VP of General Cousel and Federal Govenment Affairs)
Sioux Falls, South Dakota
false
false
13
Bleau Lafave (VP Asset Management & Business Development)
Sioux Falls, South Dakota
false
false
14
Bobbi Schroeppel (VP Customer Care, Communications, and Human Resources)
Sioux Falls, South Dakota
false
false
15
Cyndee Fang (VP Regulatory Affairs)
Sioux Falls, South Dakota
false
false
16
Jason Merkel (VP Distribution)
Sioux Falls, South Dakota
false
false
17
Jeanne Vold (VP Technology)
Sioux Falls, South Dakota
false
false
18
John Hines (VP Supply and Montana Government Affairs)
Sioux Falls, South Dakota
false
false
19
Michael Cashell (VP Transmission)
Sioux Falls, South Dakota
false
false


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
INFORMATION ON FORMULA RATES
Does the respondent have formula rates?
Yes

No
  1. Please list the Commission accepted formula rates including FERC Rate Schedule or Tariff Number and FERC proceeding (i.e. Docket No) accepting the rate(s) or changes in the accepted rate.
Line No.
RateScheduleTariffNumber
FERC Rate Schedule or Tariff Number
(a)
ProceedingDocketNumber
FERC Proceeding
(b)
1
Addendum 27 to Attachment H of Southwest Power Pool Open Access Transmission Tariff
ER20-1090-000 and ER20-1961-001 (not consolidated)
2
Addendum 27 to Attachment H of Southwest Power Pool Open Access Transmission Tariff
ER22-333-000
3
Montana OATT, Attachment O, Formula Rate Protocols and Template
ER19-1756-001
4
Montana OATT, Attachment O, Formula Rate Protocols and Template
ER21-779-000


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
INFORMATION ON FORMULA RATES - FERC Rate Schedule/Tariff Number FERC Proceeding
Does the respondent file with the Commission annual (or more frequent) filings containing the inputs to the formula rate(s)?
Yes

No
  1. If yes, provide a listing of such filings as contained on the Commission's eLibrary website.
Line No.
AccessionNumber
Accession No.
(a)
DocumentDate
Document Date / Filed Date
(b)
DocketNumber
Docket No.
(c)
DescriptionOfFiling
Description
(d)
RateScheduleTariffNumber
Formula Rate FERC Rate Schedule Number or Tariff Number
(e)
1
12/15/2023
ER24-690-000
Annual Informational Attachment H Filing of NorthWestern Corporation (South Dakota) (Rate Year 2023)
Addendum 27 to Attachment H of Southwest Power Pool Open Access Transmission Tariff
2
12/04/2023
ER24-532-000
Informational Filing of June 1, 2023, to May 31, 2024, Formula Rate Annual Update of NorthWestern Corporation (Montana)
Montana OATT, Attachment O, Formula Rate Protocols and Template


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
INFORMATION ON FORMULA RATES - Formula Rate Variances
  1. If a respondent does not submit such filings then indicate in a footnote to the applicable Form 1 schedule where formula rate inputs differ from amounts reported in the Form 1.
  2. The footnote should provide a narrative description explaining how the "rate" (or billing) was derived if different from the reported amount in the Form 1.
  3. The footnote should explain amounts excluded from the ratebase or where labor or other allocation factors, operating expenses, or other items impacting formula rate inputs differ from amounts reported in Form 1 schedule amounts.
  4. Where the Commission has provided guidance on formula rate inputs, the specific proceeding should be noted in the footnote.
Line No.
PageNumberOfFormulaRateVariances
Page No(s).
(a)
ScheduleOfFormulaRateVariances
Schedule
(b)
ColumnOfFormulaRateVariances
Column
(c)
LineNumberOfFormulaRateVariances
Line No.
(d)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
IMPORTANT CHANGES DURING THE QUARTER/YEAR

Give particulars (details) concerning the matters indicated below. Make the statements explicit and precise, and number them in accordance with the inquiries. Each inquiry should be answered. Enter "none," "not applicable," or "NA" where applicable. If information which answers an inquiry is given elsewhere in the report, make a reference to the schedule in which it appears.

  1. Changes in and important additions to franchise rights: Describe the actual consideration given therefore and state from whom the franchise rights were acquired. If acquired without the payment of consideration, state that fact.
  2. Acquisition of ownership in other companies by reorganization, merger, or consolidation with other companies: Give names of companies involved, particulars concerning the transactions, name of the Commission authorizing the transaction, and reference to Commission authorization.
  3. Purchase or sale of an operating unit or system: Give a brief description of the property, and of the transactions relating thereto, and reference to Commission authorization, if any was required. Give date journal entries called for by the Uniform System of Accounts were submitted to the Commission.
  4. Important leaseholds (other than leaseholds for natural gas lands) that have been acquired or given, assigned or surrendered: Give effective dates, lengths of terms, names of parties, rents, and other condition. State name of Commission authorizing lease and give reference to such authorization.
  5. Important extension or reduction of transmission or distribution system: State territory added or relinquished and date operations began or ceased and give reference to Commission authorization, if any was required. State also the approximate number of customers added or lost and approximate annual revenues of each class of service. Each natural gas company must also state major new continuing sources of gas made available to it from purchases, development, purchase contract or otherwise, giving location and approximate total gas volumes available, period of contracts, and other parties to any such arrangements, etc.
  6. Obligations incurred as a result of issuance of securities or assumption of liabilities or guarantees including issuance of short-term debt and commercial paper having a maturity of one year or less. Give reference to FERC or State Commission authorization, as appropriate, and the amount of obligation or guarantee.
  7. Changes in articles of incorporation or amendments to charter: Explain the nature and purpose of such changes or amendments.
  8. State the estimated annual effect and nature of any important wage scale changes during the year.
  9. State briefly the status of any materially important legal proceedings pending at the end of the year, and the results of any such proceedings culminated during the year.
  10. Describe briefly any materially important transactions of the respondent not disclosed elsewhere in this report in which an officer, director, security holder reported on Pages 104 or 105 of the Annual Report Form No. 1, voting trustee, associated company or known associate of any of these persons was a party or in which any such person had a material interest.
  11. (Reserved.)
  12. If the important changes during the year relating to the respondent company appearing in the annual report to stockholders are applicable in every respect and furnish the data required by Instructions 1 to 11 above, such notes may be included on this page.
  13. Describe fully any changes in officers, directors, major security holders and voting powers of the respondent that may have occurred during the reporting period.
  14. In the event that the respondent participates in a cash management program(s) and its proprietary capital ratio is less than 30 percent please describe the significant events or transactions causing the proprietary capital ratio to be less than 30 percent, and the extent to which the respondent has amounts loaned or money advanced to its parent, subsidiary, or affiliated companies through a cash management program(s). Additionally, please describe plans, if any to regain at least a 30 percent proprietary ratio.
1) None
2) 2. On June 1, 2022, we filed a legal corporate restructuring application (Restructuring Plan) with the state commissions in Montana, South Dakota, and Nebraska and the Federal Energy Regulatory Commission. We received all necessary regulatory approvals to effectuate this Restructuring Plan.

On October 2, 2023, NorthWestern Corporation and NorthWestern Energy Group, Inc. completed the reorganization into a holding company structure. In this reorganization, shareholders of Northwestern Corporation (the predecessor publicly held parent company) became shareholders of Northwestern Energy Group, Inc., maintaining the same number of shares and ownership percentage as held in Northwestern Corporation immediately prior to the reorganization. Northwestern Corporation became a wholly-owned subsidiary of Northwestern Energy Group, Inc. On January 1, 2024, we completed the second and final phase of the holding company reorganization. NorthWestern Corporation contributed the assets and liabilities of its South Dakota and Nebraska regulated utilities to NorthWestern Energy Public Service Corporation, and then distributed its equity interest in NorthWestern Energy Public Service Corporation and certain other subsidiaries to NorthWestern Energy Group, Inc., resulting in NorthWestern Corporation owning and operating the Montana regulated utility and NorthWestern Energy Public Service Corporation owning and operating the Nebraska and South Dakota utilities, each as a direct subsidiary of NorthWestern Energy Group, Inc.
3. On January 16, 2023, we entered into a definitive agreement (the Avista Agreement) with Avista Corporation (Avista) to acquire Avista's 15 percent interest in each of Units 3 and 4 at the Colstrip Generating Station, a coal-fired, base-load electric generation facility located in Colstrip, Montana. The Avista Agreement provides that the purchase price will be $0 and that we will acquire Avista's interest effective December 31, 2025, subject to the satisfaction of the closing conditions contained within the Avista Agreement. Under the terms of this Avista Agreement, we will be responsible for operating costs starting on January 1, 2026; while Avista will retain responsibility for its pre-closing share of environmental and pension liabilities attributed to events or conditions existing prior to the closing of the transaction and for any future decommission and demolition costs associated with the existing facilities that comprise Avista's interest.

The Avista Agreement contains customary representations and warranties, covenants, and indemnification obligations, and the Avista Agreement is subject to customary conditions and approvals, including approval from the FERC. As the terms of this agreement are not effective until January 1, 2026, and given the aforementioned conditions and approvals needed, no journal entries have been submitted to the Commission at this time.
4) None
5) None
6. See Note 11 "Unsecured Credit Facilities" Amendment to Credit Facility and Additional Credit Facility and Note 18, "Common Stock" Equity issuance: FERC Order ES23-53-000 and MPSC Order Number 7091 Docket Number D2023.07.062
7) We amended our articles of incorporation on September 29th, 2023 in connection with the reorganization described in item 2, See item 2 for more information
8) None
9) See Note 19, "Commitments and Contingencies".
10) None
12) None
13. On January 1, 2023, Bob Rowe retired as Chief Executive Officer and Brian Bird was promoted to President and Chief Executive Officer.

On January 1, 2023, Heather Grahame retired as General Counsel and Vice President - Regulatory and Federal Government Affairs. On this same day, Cyndee Fang was promoted to Vice President - Regulatory and Shannon Heim was promoted to Vice President - General Counsel.

On April 28, 2023, Sherina Edwards was elected by our shareholders to the Board of Directors.

On June 16, 2023, Curt Pohl retired as Vice President of Asset Management and Business Development and Bleau LaFave was promoted to Vice President of Asset Management and Business Development.

On October 2, 2023, pursuant to the merger referenced in item 2 above, the Directors of NorthWestern Corporation retired from their positions and became Directors of NorthWestern Energy Group, Inc. These Directors were replaced with the existing Officers of NorthWestern Corporation. As such, on October 2, 2023, the Directors of NorthWestern Corporation are as follows:
–Brian Bird;
–Crystal Lail;
–Shannon Heim;
–Michael Cashell;
–Cyndee Fang;
–John Hines;
–Bleau Lafave;
–Jason Merkel;
–Bobbi Schroeppel; and
–Jeanne Vold

Further, as pursuant to the merger referenced in item 2 above, shareholders of Northwestern Corporation (the predecessor publicly held parent company) became shareholders of Northwestern Energy Group, Inc., maintaining the same number of shares and ownership percentage as held in Northwestern Corporation immediately prior to the reorganization. Northwestern Corporation became a wholly-owned subsidiary of Northwestern Energy Group, Inc.
14) NA


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
COMPARATIVE BALANCE SHEET (ASSETS AND OTHER DEBITS)
Line No.
Title of Account
(a)
Ref. Page No.
(b)
Current Year End of Quarter/Year Balance
(c)
Prior Year End Balance 12/31
(d)
1
UtilityPlantAbstract
UTILITY PLANT
2
UtilityPlant
Utility Plant (101-106, 114)
200
7,983,112,655
7,591,279,874
3
ConstructionWorkInProgress
Construction Work in Progress (107)
200
358,401,452
300,649,215
4
UtilityPlantAndConstructionWorkInProgress
TOTAL Utility Plant (Enter Total of lines 2 and 3)
8,341,514,107
7,891,929,089
5
AccumulatedProvisionForDepreciationAmortizationAndDepletionOfPlantUtility
(Less) Accum. Prov. for Depr. Amort. Depl. (108, 110, 111, 115)
200
2,874,902,417
2,786,711,964
6
UtilityPlantNet
Net Utility Plant (Enter Total of line 4 less 5)
5,466,611,690
5,105,217,125
7
NuclearFuelInProcessOfRefinementConversionEnrichmentAndFabrication
Nuclear Fuel in Process of Ref., Conv., Enrich., and Fab. (120.1)
202
8
NuclearFuelMaterialsAndAssembliesStockAccountMajorOnly
Nuclear Fuel Materials and Assemblies-Stock Account (120.2)
9
NuclearFuelAssembliesInReactorMajorOnly
Nuclear Fuel Assemblies in Reactor (120.3)
10
SpentNuclearFuelMajorOnly
Spent Nuclear Fuel (120.4)
11
NuclearFuelUnderCapitalLeases
Nuclear Fuel Under Capital Leases (120.6)
12
AccumulatedProvisionForAmortizationOfNuclearFuelAssemblies
(Less) Accum. Prov. for Amort. of Nucl. Fuel Assemblies (120.5)
202
13
NuclearFuelNet
Net Nuclear Fuel (Enter Total of lines 7-11 less 12)
14
UtilityPlantAndNuclearFuelNet
Net Utility Plant (Enter Total of lines 6 and 13)
5,466,611,690
5,105,217,125
15
OtherElectricPlantAdjustments
Utility Plant Adjustments (116)
357,585,527
357,585,527
16
GasStoredUndergroundNoncurrent
Gas Stored Underground - Noncurrent (117)
36,212,426
36,209,611
17
OtherPropertyAndInvestmentsAbstract
OTHER PROPERTY AND INVESTMENTS
18
NonutilityProperty
Nonutility Property (121)
686,805
686,805
19
AccumulatedProvisionForDepreciationAndAmortizationOfNonutilityProperty
(Less) Accum. Prov. for Depr. and Amort. (122)
67,635
65,534
20
InvestmentInAssociatedCompanies
Investments in Associated Companies (123)
21
InvestmentInSubsidiaryCompanies
Investment in Subsidiary Companies (123.1)
224
33,374,273
25,343,937
23
NoncurrentPortionOfAllowances
Noncurrent Portion of Allowances
228
24
OtherInvestments
Other Investments (124)
13,050,811
21,035,719
25
SinkingFunds
Sinking Funds (125)
26
DepreciationFund
Depreciation Fund (126)
27
AmortizationFundFederal
Amortization Fund - Federal (127)
28
OtherSpecialFunds
Other Special Funds (128)
29
SpecialFunds
Special Funds (Non Major Only) (129)
30
DerivativeInstrumentAssetsLongTerm
Long-Term Portion of Derivative Assets (175)
31
DerivativeInstrumentAssetsHedgesLongTerm
Long-Term Portion of Derivative Assets - Hedges (176)
32
OtherPropertyAndInvestments
TOTAL Other Property and Investments (Lines 18-21 and 23-31)
47,044,254
47,000,927
33
CurrentAndAccruedAssetsAbstract
CURRENT AND ACCRUED ASSETS
34
CashAndWorkingFunds
Cash and Working Funds (Non-major Only) (130)
35
Cash
Cash (131)
8,740,865
8,029,111
36
SpecialDeposits
Special Deposits (132-134)
14,856,653
12,761,965
37
WorkingFunds
Working Fund (135)
22,850
23,450
38
TemporaryCashInvestments
Temporary Cash Investments (136)
39
NotesReceivable
Notes Receivable (141)
40
CustomerAccountsReceivable
Customer Accounts Receivable (142)
91,004,512
106,890,491
41
OtherAccountsReceivable
Other Accounts Receivable (143)
17,049,224
26,793,907
42
AccumulatedProvisionForUncollectibleAccountsCredit
(Less) Accum. Prov. for Uncollectible Acct.-Credit (144)
2,813,091
2,451,237
43
NotesReceivableFromAssociatedCompanies
Notes Receivable from Associated Companies (145)
44
AccountsReceivableFromAssociatedCompanies
Accounts Receivable from Assoc. Companies (146)
615,046
3,143,188
45
FuelStock
Fuel Stock (151)
227
9,710,818
7,724,941
46
FuelStockExpensesUndistributed
Fuel Stock Expenses Undistributed (152)
227
47
Residuals
Residuals (Elec) and Extracted Products (153)
227
48
PlantMaterialsAndOperatingSupplies
Plant Materials and Operating Supplies (154)
227
85,254,493
71,154,248
49
Merchandise
Merchandise (155)
227
50
OtherMaterialsAndSupplies
Other Materials and Supplies (156)
227
51
NuclearMaterialsHeldForSale
Nuclear Materials Held for Sale (157)
202/227
52
AllowanceInventoryAndWithheld
Allowances (158.1 and 158.2)
228
53
NoncurrentPortionOfAllowances
(Less) Noncurrent Portion of Allowances
228
54
StoresExpenseUndistributed
Stores Expense Undistributed (163)
227
55
GasStoredCurrent
Gas Stored Underground - Current (164.1)
18,814,211
27,722,831
56
LiquefiedNaturalGasStoredAndHeldForProcessing
Liquefied Natural Gas Stored and Held for Processing (164.2-164.3)
57
Prepayments
Prepayments (165)
(a)
21,740,289
23,739,745
58
AdvancesForGas
Advances for Gas (166-167)
59
InterestAndDividendsReceivable
Interest and Dividends Receivable (171)
60
RentsReceivable
Rents Receivable (172)
73,787
213,473
61
AccruedUtilityRevenues
Accrued Utility Revenues (173)
105,109,956
117,418,484
62
MiscellaneousCurrentAndAccruedAssets
Miscellaneous Current and Accrued Assets (174)
876,036
2,372,750
63
DerivativeInstrumentAssets
Derivative Instrument Assets (175)
64
DerivativeInstrumentAssetsLongTerm
(Less) Long-Term Portion of Derivative Instrument Assets (175)
65
DerivativeInstrumentAssetsHedges
Derivative Instrument Assets - Hedges (176)
66
DerivativeInstrumentAssetsHedgesLongTerm
(Less) Long-Term Portion of Derivative Instrument Assets - Hedges (176)
67
CurrentAndAccruedAssets
Total Current and Accrued Assets (Lines 34 through 66)
371,055,649
405,537,347
68
DeferredDebitsAbstract
DEFERRED DEBITS
69
UnamortizedDebtExpense
Unamortized Debt Expenses (181)
11,096,631
9,254,937
70
ExtraordinaryPropertyLosses
Extraordinary Property Losses (182.1)
230a
71
UnrecoveredPlantAndRegulatoryStudyCosts
Unrecovered Plant and Regulatory Study Costs (182.2)
230b
72
OtherRegulatoryAssets
Other Regulatory Assets (182.3)
232
746,025,553
729,084,376
73
PreliminarySurveyAndInvestigationCharges
Prelim. Survey and Investigation Charges (Electric) (183)
376,264
74
PreliminaryNaturalGasSurveyAndInvestigationChargesAndOtherPreliminarySurveyAndInvestigationCharges
Preliminary Natural Gas Survey and Investigation Charges 183.1)
75
OtherPreliminarySurveyAndInvestigationCharges
Other Preliminary Survey and Investigation Charges (183.2)
76
ClearingAccounts
Clearing Accounts (184)
2,522
37,192
77
TemporaryFacilities
Temporary Facilities (185)
78
MiscellaneousDeferredDebits
Miscellaneous Deferred Debits (186)
233
11,084,645
9,543,157
79
DeferredLossesFromDispositionOfUtilityPlant
Def. Losses from Disposition of Utility Plt. (187)
80
ResearchDevelopmentAndDemonstrationExpenditures
Research, Devel. and Demonstration Expend. (188)
352
81
UnamortizedLossOnReacquiredDebt
Unamortized Loss on Reaquired Debt (189)
(b)
20,027,942
22,619,741
82
AccumulatedDeferredIncomeTaxes
Accumulated Deferred Income Taxes (190)
234
289,883,014
163,943,624
83
UnrecoveredPurchasedGasCosts
Unrecovered Purchased Gas Costs (191)
3,394,843
100,874,939
84
DeferredDebits
Total Deferred Debits (lines 69 through 83)
1,081,886,370
1,035,357,966
85
AssetsAndOtherDebits
TOTAL ASSETS (lines 14-16, 32, 67, and 84)
7,360,395,916
6,986,908,503


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
FOOTNOTE DATA

(a) Concept: Prepayments
South Dakota Operations Prepayments (165) are $10,510,220 and $11,517,440 for 2023 and 2022, respectively.

Montana Operations Prepayments (165) are $11,230,070 and $12,222,305 for 2023 and 2022, respectively.
(b) Concept: UnamortizedLossOnReacquiredDebt
Montana Operations Unamortized Loss on Reacquired Debt (189) is $18,539,713 and $20,416,114 for 2023 and 2022, respectively.

Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
COMPARATIVE BALANCE SHEET (LIABILITIES AND OTHER CREDITS)
Line No.
Title of Account
(a)
Ref. Page No.
(b)
Current Year End of Quarter/Year Balance
(c)
Prior Year End Balance 12/31
(d)
1
ProprietaryCapitalAbstract
PROPRIETARY CAPITAL
2
CommonStockIssued
Common Stock Issued (201)
250
1
632,782
3
PreferredStockIssued
Preferred Stock Issued (204)
250
4
CapitalStockSubscribed
Capital Stock Subscribed (202, 205)
5
StockLiabilityForConversion
Stock Liability for Conversion (203, 206)
6
PremiumOnCapitalStock
Premium on Capital Stock (207)
7
OtherPaidInCapital
Other Paid-In Capital (208-211)
253
1,981,122,791
1,999,375,991
8
InstallmentsReceivedOnCapitalStock
Installments Received on Capital Stock (212)
252
9
DiscountOnCapitalStock
(Less) Discount on Capital Stock (213)
254
10
CapitalStockExpense
(Less) Capital Stock Expense (214)
254b
11
RetainedEarnings
Retained Earnings (215, 215.1, 216)
118
810,816,636
769,493,168
12
UnappropriatedUndistributedSubsidiaryEarnings
Unappropriated Undistributed Subsidiary Earnings (216.1)
118
1,503,684
222,330
13
ReacquiredCapitalStock
(Less) Reacquired Capital Stock (217)
250
98,392,040
14
NoncorporateProprietorship
Noncorporate Proprietorship (Non-major only) (218)
15
AccumulatedOtherComprehensiveIncome
Accumulated Other Comprehensive Income (219)
122(a)(b)
5,513,000
5,705,664
16
ProprietaryCapital
Total Proprietary Capital (lines 2 through 15)
2,784,922,744
2,665,181,907
17
LongTermDebtAbstract
LONG-TERM DEBT
18
Bonds
Bonds (221)
256
2,479,660,000
2,179,660,000
19
ReacquiredBonds
(Less) Reacquired Bonds (222)
256
20
AdvancesFromAssociatedCompanies
Advances from Associated Companies (223)
256
21
OtherLongTermDebt
Other Long-Term Debt (224)
256
318,000,000
450,000,000
22
UnamortizedPremiumOnLongTermDebt
Unamortized Premium on Long-Term Debt (225)
23
UnamortizedDiscountOnLongTermDebtDebit
(Less) Unamortized Discount on Long-Term Debt-Debit (226)
6,538
33,056
24
LongTermDebt
Total Long-Term Debt (lines 18 through 23)
2,797,653,462
2,629,626,944
25
OtherNoncurrentLiabilitiesAbstract
OTHER NONCURRENT LIABILITIES
26
ObligationsUnderCapitalLeaseNoncurrent
Obligations Under Capital Leases - Noncurrent (227)
5,996,448
9,389,857
27
AccumulatedProvisionForPropertyInsurance
Accumulated Provision for Property Insurance (228.1)
28
AccumulatedProvisionForInjuriesAndDamages
Accumulated Provision for Injuries and Damages (228.2)
(a)
6,745,658
4,365,711
29
AccumulatedProvisionForPensionsAndBenefits
Accumulated Provision for Pensions and Benefits (228.3)
(b)
4,631,028
10,546,632
30
AccumulatedMiscellaneousOperatingProvisions
Accumulated Miscellaneous Operating Provisions (228.4)
50,272,082
72,588,961
31
AccumulatedProvisionForRateRefunds
Accumulated Provision for Rate Refunds (229)
32
LongTermPortionOfDerivativeInstrumentLiabilities
Long-Term Portion of Derivative Instrument Liabilities
33
LongTermPortionOfDerivativeInstrumentLiabilitiesHedges
Long-Term Portion of Derivative Instrument Liabilities - Hedges
34
AssetRetirementObligations
Asset Retirement Obligations (230)
41,424,213
40,893,877
35
OtherNoncurrentLiabilities
Total Other Noncurrent Liabilities (lines 26 through 34)
109,069,429
137,785,038
36
CurrentAndAccruedLiabilitiesAbstract
CURRENT AND ACCRUED LIABILITIES
37
NotesPayable
Notes Payable (231)
92,402
38
AccountsPayable
Accounts Payable (232)
(c)
131,709,370
214,538,891
39
NotesPayableToAssociatedCompanies
Notes Payable to Associated Companies (233)
40
AccountsPayableToAssociatedCompanies
Accounts Payable to Associated Companies (234)
4,804,188
4,356,816
41
CustomerDeposits
Customer Deposits (235)
11,954,099
10,853,645
42
TaxesAccrued
Taxes Accrued (236)
262
(d)
75,992,477
92,522,773
43
InterestAccrued
Interest Accrued (237)
24,775,303
18,349,945
44
DividendsDeclared
Dividends Declared (238)
45
MaturedLongTermDebt
Matured Long-Term Debt (239)
46
MaturedInterest
Matured Interest (240)
47
TaxCollectionsPayable
Tax Collections Payable (241)
1,789,013
2,441,695
48
MiscellaneousCurrentAndAccruedLiabilities
Miscellaneous Current and Accrued Liabilities (242)
(e)
73,408,287
72,402,424
49
ObligationsUnderCapitalLeasesCurrent
Obligations Under Capital Leases-Current (243)
3,720,377
3,802,179
50
DerivativesInstrumentLiabilities
Derivative Instrument Liabilities (244)
51
LongTermPortionOfDerivativeInstrumentLiabilities
(Less) Long-Term Portion of Derivative Instrument Liabilities
52
DerivativeInstrumentLiabilitiesHedges
Derivative Instrument Liabilities - Hedges (245)
53
LongTermPortionOfDerivativeInstrumentLiabilitiesHedges
(Less) Long-Term Portion of Derivative Instrument Liabilities-Hedges
54
CurrentAndAccruedLiabilities
Total Current and Accrued Liabilities (lines 37 through 53)
328,153,114
419,360,770
55
DeferredCreditsAbstract
DEFERRED CREDITS
56
CustomerAdvancesForConstruction
Customer Advances for Construction (252)
(f)
107,470,505
95,393,208
57
AccumulatedDeferredInvestmentTaxCredits
Accumulated Deferred Investment Tax Credits (255)
266
258,964
388,447
58
DeferredGainsFromDispositionOfUtilityPlant
Deferred Gains from Disposition of Utility Plant (256)
59
OtherDeferredCredits
Other Deferred Credits (253)
269
147,334,417
158,152,503
60
OtherRegulatoryLiabilities
Other Regulatory Liabilities (254)
278
190,647,029
171,400,902
61
UnamortizedGainOnReacquiredDebt
Unamortized Gain on Reacquired Debt (257)
62
AccumulatedDeferredIncomeTaxesAcceleratedAmortizationProperty
Accum. Deferred Income Taxes-Accel. Amort.(281)
272
63
AccumulatedDeferredIncomeTaxesOtherProperty
Accum. Deferred Income Taxes-Other Property (282)
663,637,584
455,220,141
64
AccumulatedDeferredIncomeTaxesOther
Accum. Deferred Income Taxes-Other (283)
231,248,668
254,398,643
65
DeferredCredits
Total Deferred Credits (lines 56 through 64)
1,340,597,167
1,134,953,844
66
LiabilitiesAndOtherCredits
TOTAL LIABILITIES AND STOCKHOLDER EQUITY (lines 16, 24, 35, 54 and 65)
7,360,395,916
6,986,908,503


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
FOOTNOTE DATA

(a) Concept: AccumulatedProvisionForInjuriesAndDamages
South Dakota Operations Provision for Injuries and Damages (228.2) are $442,867 and $480,925 for 2023 and 2022, respectively.
Montana Operations Provision for Injuries and Damages (228.2) are $6,302,791 and $3,884,786 for 2023 and 2022, respectively.
(b) Concept: AccumulatedProvisionForPensionsAndBenefits
Montana Operations Accumulated Provision for Pensions and Benefits (228.3) are $1,308,934 and 7,048,754 for 2023 and 2022, respectively.
(c) Concept: AccountsPayable
Montana Operations unfunded reserves for Accounts Payable (232) are $2,120,217 and $2,019,947 for 2023 and 2022, respectively
(d) Concept: TaxesAccrued
Montana Operations unfunded reserves for Taxes Accrued (236) are $72,794,059 and $88,508,843 for 2023 and 2022, respectively.
(e) Concept: MiscellaneousCurrentAndAccruedLiabilities
Montana Operations Miscellaneous Current and Accrued Liabilities (242) are $61,018,856 and $60,534,114 for 2023 and 2022, respectively.

Montana Operations unfunded reserve for Miscellaneous Current and Accrued Liabilities (242) are $20,948,018 and $23,181,621 for 2023 and 2022, respectively.
(f) Concept: CustomerAdvancesForConstruction
Montana Operations Customer Advances for Construction (252) are $107,470,505 and $95,393,208 for 2023 and 2022, respectively.

Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
STATEMENT OF INCOME

Quarterly

  1. Report in column (c) the current year to date balance. Column (c) equals the total of adding the data in column (g) plus the data in column (i) plus the data in column (k). Report in column (d) similar data for the previous year. This information is reported in the annual filing only.
  2. Enter in column (e) the balance for the reporting quarter and in column (f) the balance for the same three month period for the prior year.
  3. Report in column (g) the quarter to date amounts for electric utility function; in column (i) the quarter to date amounts for gas utility, and in column (k) the quarter to date amounts for other utility function for the current year quarter.
  4. Report in column (h) the quarter to date amounts for electric utility function; in column (j) the quarter to date amounts for gas utility, and in column (l) the quarter to date amounts for other utility function for the prior year quarter.
  5. If additional columns are needed, place them in a footnote.

Annual or Quarterly if applicable

  1. Do not report fourth quarter data in columns (e) and (f)
  2. Report amounts for accounts 412 and 413, Revenues and Expenses from Utility Plant Leased to Others, in another utility column in a similar manner to a utility department. Spread the amount(s) over Lines 2 thru 26 as appropriate. Include these amounts in columns (c) and (d) totals.
  3. Report amounts in account 414, Other Utility Operating Income, in the same manner as accounts 412 and 413 above.
  4. Use page 122 for important notes regarding the statement of income for any account thereof.
  5. Give concise explanations concerning unsettled rate proceedings where a contingency exists such that refunds of a material amount may need to be made to the utility's customers or which may result in material refund to the utility with respect to power or gas purchases. State for each year effected the gross revenues or costs to which the contingency relates and the tax effects together with an explanation of the major factors which affect the rights of the utility to retain such revenues or recover amounts paid with respect to power or gas purchases.
  6. Give concise explanations concerning significant amounts of any refunds made or received during the year resulting from settlement of any rate proceeding affecting revenues received or costs incurred for power or gas purchases, and a summary of the adjustments made to balance sheet, income, and expense accounts.
  7. If any notes appearing in the report to stockholders are applicable to the Statement of Income, such notes may be included at page 122.
  8. Enter on page 122 a concise explanation of only those changes in accounting methods made during the year which had an effect on net income, including the basis of allocations and apportionments from those used in the preceding year. Also, give the appropriate dollar effect of such changes.
  9. Explain in a footnote if the previous year's/quarter's figures are different from that reported in prior reports.
  10. If the columns are insufficient for reporting additional utility departments, supply the appropriate account titles report the information in a footnote to this schedule.
Line No.
Title of Account
(a)
(Ref.) Page No.
(b)
Total Current Year to Date Balance for Quarter/Year
(c)
Total Prior Year to Date Balance for Quarter/Year
(d)
Current 3 Months Ended - Quarterly Only - No 4th Quarter
(e)
Prior 3 Months Ended - Quarterly Only - No 4th Quarter
(f)
Electric Utility Current Year to Date (in dollars)
(g)
Electric Utility Previous Year to Date (in dollars)
(h)
Gas Utiity Current Year to Date (in dollars)
(i)
Gas Utility Previous Year to Date (in dollars)
(j)
Other Utility Current Year to Date (in dollars)
(k)
Other Utility Previous Year to Date (in dollars)
(l)
1
UtilityOperatingIncomeAbstract
UTILITY OPERATING INCOME
2
OperatingRevenues
Operating Revenues (400)
300
1,658,678,800
1,524,197,364
1,282,105,235
1,127,210,087
375,425,391
396,009,572
1,148,174
977,705
3
OperatingExpensesAbstract
Operating Expenses
4
OperationExpense
Operation Expenses (401)
320
890,436,496
809,878,523
646,055,016
544,662,719
243,441,581
264,442,231
939,899
773,573
5
MaintenanceExpense
Maintenance Expenses (402)
320
56,287,320
59,014,835
47,406,239
50,136,264
8,848,386
8,825,579
32,695
52,992
6
DepreciationExpense
Depreciation Expense (403)
336
179,851,232
167,041,787
149,308,812
139,754,512
29,655,013
27,246,571
40,901
40,704
7
DepreciationExpenseForAssetRetirementCosts
Depreciation Expense for Asset Retirement Costs (403.1)
336
8
AmortizationAndDepletionOfUtilityPlant
Amort. & Depl. of Utility Plant (404-405)
336
15,879,321
13,044,982
9,619,264
7,316,584
6,260,057
5,728,398
9
AmortizationOfElectricPlantAcquisitionAdjustments
Amort. of Utility Plant Acq. Adj. (406)
336
15,101,772
15,101,772
(b)
15,948,277
15,948,277
846,505
10
AmortizationOfPropertyLossesUnrecoveredPlantAndRegulatoryStudyCosts
Amort. Property Losses, Unrecov Plant and Regulatory Study Costs (407)
11
AmortizationOfConversionExpenses
Amort. of Conversion Expenses (407.2)
12
RegulatoryDebits
Regulatory Debits (407.3)
83,200,914
33,744,634
53,116,240
16,669,247
30,084,675
17,075,387
13
RegulatoryCredits
(Less) Regulatory Credits (407.4)
45,339,571
45,594,098
25,928,597
28,249,541
19,410,974
17,344,557
14
TaxesOtherThanIncomeTaxesUtilityOperatingIncome
Taxes Other Than Income Taxes (408.1)
262
163,049,808
200,534,577
126,571,887
155,802,375
36,431,466
44,668,842
46,455
63,360
15
IncomeTaxesOperatingIncome
Income Taxes - Federal (409.1)
262
3,150,973
9,971,297
4,010,306
3,139,051
7,183,190
6,821,766
21,911
10,480
16
IncomeTaxesUtilityOperatingIncomeOther
Income Taxes - Other (409.1)
262
2,335,146
2,754,621
429,564
448,741
2,772,263
2,302,267
7,553
3,613
17
ProvisionsForDeferredIncomeTaxesUtilityOperatingIncome
Provision for Deferred Income Taxes (410.1)
234, 272
301,078,323
127,918,489
219,290,850
93,412,247
81,799,417
34,505,957
11,944
285
18
ProvisionForDeferredIncomeTaxesCreditOperatingIncome
(Less) Provision for Deferred Income Taxes-Cr. (411.1)
234, 272
290,267,630
141,345,530
212,486,809
99,409,405
77,780,820
41,936,125
19
InvestmentTaxCreditAdjustments
Investment Tax Credit Adj. - Net (411.4)
266
129,483
129,521
129,482
129,521
20
GainsFromDispositionOfPlant
(Less) Gains from Disp. of Utility Plant (411.6)
21
LossesFromDispositionOfServiceCompanyPlant
Losses from Disp. of Utility Plant (411.7)
22
GainsFromDispositionOfAllowances
(Less) Gains from Disposition of Allowances (411.8)
3
3
23
LossesFromDispositionOfAllowances
Losses from Disposition of Allowances (411.9)
24
AccretionExpense
Accretion Expense (411.10)
25
UtilityOperatingExpenses
TOTAL Utility Operating Expenses (Enter Total of lines 4 thru 24)
1,363,662,383
1,251,936,365
1,033,211,567
899,501,547
329,373,348
351,489,811
1,077,470
945,007
27
NetUtilityOperatingIncome
Net Util Oper Inc (Enter Tot line 2 less 25)
295,016,417
272,260,999
248,893,668
227,708,540
46,052,043
44,519,761
70,704
32,698
28
OtherIncomeAndDeductionsAbstract
Other Income and Deductions
29
OtherIncomeAbstract
Other Income
30
NonutilityOperatingIncomeAbstract
Nonutilty Operating Income
31
RevenuesFromMerchandisingJobbingAndContractWork
Revenues From Merchandising, Jobbing and Contract Work (415)
572,017
507,851
32
CostsAndExpensesOfMerchandisingJobbingAndContractWork
(Less) Costs and Exp. of Merchandising, Job. & Contract Work (416)
198,753
486,559
33
RevenuesFromNonutilityOperations
Revenues From Nonutility Operations (417)
166,027
255,417
34
ExpensesOfNonutilityOperations
(Less) Expenses of Nonutility Operations (417.1)
513,794
535,233
35
NonoperatingRentalIncome
Nonoperating Rental Income (418)
36
EquityInEarningsOfSubsidiaryCompanies
Equity in Earnings of Subsidiary Companies (418.1)
119
1,281,354
668,404
37
InterestAndDividendIncome
Interest and Dividend Income (419)
437,731
2,150,974
38
AllowanceForOtherFundsUsedDuringConstruction
Allowance for Other Funds Used During Construction (419.1)
17,612,998
14,189,693
39
MiscellaneousNonoperatingIncome
Miscellaneous Nonoperating Income (421)
78,654
414,852
40
GainOnDispositionOfProperty
Gain on Disposition of Property (421.1)
41
OtherIncome
TOTAL Other Income (Enter Total of lines 31 thru 40)
16,873,526
14,998,887
42
OtherIncomeDeductionsAbstract
Other Income Deductions
43
LossOnDispositionOfProperty
Loss on Disposition of Property (421.2)
44
MiscellaneousAmortization
Miscellaneous Amortization (425)
45
Donations
Donations (426.1)
1,009,410
987,589
46
LifeInsurance
Life Insurance (426.2)
47
Penalties
Penalties (426.3)
3,196
2,543,918
48
ExpendituresForCertainCivicPoliticalAndRelatedActivities
Exp. for Certain Civic, Political & Related Activities (426.4)
377,026
333,624
49
OtherDeductions
Other Deductions (426.5)
1,589,981
253,101
50
OtherIncomeDeductions
TOTAL Other Income Deductions (Total of lines 43 thru 49)
2,979,613
4,118,232
51
TaxesApplicableToOtherIncomeAndDeductionsAbstract
Taxes Applic. to Other Income and Deductions
52
TaxesOtherThanIncomeTaxesOtherIncomeAndDeductions
Taxes Other Than Income Taxes (408.2)
262
1,550,307
2,160
53
IncomeTaxesFederal
Income Taxes-Federal (409.2)
262
2,971,276
6,388,081
54
IncomeTaxesOther
Income Taxes-Other (409.2)
262
350,353
1,203,627
55
ProvisionForDeferredIncomeTaxesOtherIncomeAndDeductions
Provision for Deferred Inc. Taxes (410.2)
234, 272
(a)
6,770,585
18,080,883
56
ProvisionForDeferredIncomeTaxesCreditOtherIncomeAndDeductions
(Less) Provision for Deferred Income Taxes-Cr. (411.2)
234, 272
10,905,042
13,616,535
57
InvestmentTaxCreditAdjustmentsNonutilityOperations
Investment Tax Credit Adj.-Net (411.5)
58
InvestmentTaxCredits
(Less) Investment Tax Credits (420)
59
TaxesOnOtherIncomeAndDeductions
TOTAL Taxes on Other Income and Deductions (Total of lines 52-58)
2,363,135
717,946
60
NetOtherIncomeAndDeductions
Net Other Income and Deductions (Total of lines 41, 50, 59)
16,257,048
11,598,601
61
InterestChargesAbstract
Interest Charges
62
InterestOnLongTermDebt
Interest on Long-Term Debt (427)
111,284,778
100,558,580
63
AmortizationOfDebtDiscountAndExpense
Amort. of Debt Disc. and Expense (428)
1,952,407
1,878,506
64
AmortizationOfLossOnReacquiredDebt
Amortization of Loss on Reaquired Debt (428.1)
2,576,003
2,828,333
65
AmortizationOfPremiumOnDebtCredit
(Less) Amort. of Premium on Debt-Credit (429)
66
AmortizationOfGainOnReacquiredDebtCredit
(Less) Amortization of Gain on Reaquired Debt-Credit (429.1)
67
InterestOnDebtToAssociatedCompanies
Interest on Debt to Assoc. Companies (430)
68
OtherInterestExpense
Other Interest Expense (431)
8,025,169
1,579,131
69
AllowanceForBorrowedFundsUsedDuringConstructionCredit
(Less) Allowance for Borrowed Funds Used During Construction-Cr. (432)
6,696,447
5,991,570
70
NetInterestCharges
Net Interest Charges (Total of lines 62 thru 69)
117,141,910
100,852,980
71
IncomeBeforeExtraordinaryItems
Income Before Extraordinary Items (Total of lines 27, 60 and 70)
194,131,555
183,006,620
72
ExtraordinaryItemsAbstract
Extraordinary Items
73
ExtraordinaryIncome
Extraordinary Income (434)
74
ExtraordinaryDeductions
(Less) Extraordinary Deductions (435)
75
NetExtraordinaryItems
Net Extraordinary Items (Total of line 73 less line 74)
76
IncomeTaxesExtraordinaryItems
Income Taxes-Federal and Other (409.3)
262
0
77
ExtraordinaryItemsAfterTaxes
Extraordinary Items After Taxes (line 75 less line 76)
78
NetIncomeLoss
Net Income (Total of line 71 and 77)
194,131,555
183,006,620


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
FOOTNOTE DATA

(a) Concept: ProvisionForDeferredIncomeTaxesOtherIncomeAndDeductions
Included in the Provision for Deferred Income Taxes, in the Statements of Income, is amortization of the excess and deficient ADIT's as follows:

Line
No.
Description (a) (b) (c) (d) (e) (f) (g)
FERC Method of Amortization RSG SL ARAM/RSG SL
Amortization period Book Lives 5 Years Book Lives 5 Years
Protected/Unprotected Protected Unprotected Protected Unprotected
FERC Amorization Account 410.1 410.1 411.1 411.1
TCJA Excess ADIT Account Reduced 190 190 Subtotal 282 283 Subtotal
Reg Asset Acccount Impacted 182.3 182.3 182.3 254 254 254
1 Montana:
2 Electric 921,625  3,823,846  4,745,471  (3,306,214) (2,446,997) (5,753,211)
3 Gas (3,384,786) 696,298  (2,688,488) (1,972,966) (521,804) (2,494,770)
4 Subtotal (2,463,161) 4,520,144  2,056,983  (5,279,180) (2,968,801) (8,247,981)
5 South Dakota:
6 Electric 138,139  —  138,139  (708,978) —  (708,978)
7 Gas (5,514) (1) (5,515) (405,957) —  (405,957)
8 Subtotal 132,625  (1) 132,624  (1,114,935) —  (1,114,935)
9 Total (2,330,536) 4,520,143  2,189,607  (6,394,115) (2,968,801) (9,362,916)


Line
No.
Description (a) (h) (i) (j) (k)
FERC Method of Amortization SL (MT) / RSG
(SD)
SL
Amortization period 5 years (MT) /
Book Lives
(SD)
5 Years
Protected/Unprotected F/T "as-if"
normalized
F/T "as-if"
normalized
FERC Amorization Account 411.1 410.1
TCJA Excess ADIT Account Reduced Total of 182.3 282 190
Reg Asset Acccount Impacted and 254 254 182.3 Total
1 Montana:
2 Electric (1,007,740) (9,824,625) 47,536  (10,784,829)
3 Gas (5,183,258) (2,831,410) 9,243  (8,005,425)
4 Subtotal (6,190,998) (12,656,035) 56,779  (18,790,254)
5 South Dakota:
6 Electric (570,839) (464,843) —  (1,035,682)
7 Gas (411,472) (75,064) —  (486,536)
8 Subtotal (982,311) (539,907) —  (1,522,218)
9 Total (7,173,309) (13,195,942) 56,779  (20,312,472)
(b) Concept: AmortizationOfElectricPlantAcquisitionAdjustments
Amort. of Utility Plant Acq. Adj. of $15,948,277 consists of $14,747,883 for Montana Operations and $1,200,394 for South Dakota Operations.

Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report


End of:
2023
/
Q4
STATEMENT OF RETAINED EARNINGS
  1. Do not report Lines 49-53 on the quarterly report.
  2. Report all changes in appropriated retained earnings, unappropriated retained earnings, and unappropriated undistributed subsidiary earnings for the year.
  3. Each credit and debit during the year should be identified as to the retained earnings account in which recorded (Accounts 433, 436-439 inclusive). Show the contra primary account affected in column (b).
  4. State the purpose and amount for each reservation or appropriation of retained earnings.
  5. List first Account 439, Adjustments to Retained Earnings, reflecting adjustments to the opening balance of retained earnings. Follow by credit, then debit items, in that order.
  6. Show dividends for each class and series of capital stock.
  7. Show separately the State and Federal income tax effect of items shown for Account 439, Adjustments to Retained Earnings.
  8. Explain in a footnote the basis for determining the amount reserved or appropriated. If such reservation or appropriation is to be recurrent, state the number and annual amounts to be reserved or appropriated as well as the totals eventually to be accumulated.
  9. If any notes appearing in the report to stockholders are applicable to this statement, attach them at page 122.
Line No.
Item
(a)
Contra Primary Account Affected
(b)
Current Quarter/Year Year to Date Balance
(c)
Previous Quarter/Year Year to Date Balance
(d)
UnappropriatedRetainedEarningsAbstract
UNAPPROPRIATED RETAINED EARNINGS (Account 216)
1
UnappropriatedRetainedEarnings
Balance-Beginning of Period
769,493,168
725,880,305
2
ChangesAbstract
Changes
3
AdjustmentsToRetainedEarningsAbstract
Adjustments to Retained Earnings (Account 439)
4
AdjustmentsToRetainedEarningsCreditAbstract
Adjustments to Retained Earnings Credit
9
AdjustmentsToRetainedEarningsCredit
TOTAL Credits to Retained Earnings (Acct. 439)
10
AdjustmentsToRetainedEarningsDebitAbstract
Adjustments to Retained Earnings Debit
15
AdjustmentsToRetainedEarningsDebit
TOTAL Debits to Retained Earnings (Acct. 439)
16
BalanceTransferredFromIncome
Balance Transferred from Income (Account 433 less Account 418.1)
195,412,909
183,675,024
17
AppropriationsOfRetainedEarningsAbstract
Appropriations of Retained Earnings (Acct. 436)
22
AppropriationsOfRetainedEarnings
TOTAL Appropriations of Retained Earnings (Acct. 436)
23
DividendsDeclaredPreferredStockAbstract
Dividends Declared-Preferred Stock (Account 437)
29
DividendsDeclaredPreferredStock
TOTAL Dividends Declared-Preferred Stock (Acct. 437)
30
DividendsDeclaredCommonStockAbstract
Dividends Declared-Common Stock (Account 438)
30.1
DividendsDeclaredCommonStock
Common Stock Dividend
154,089,441
140,062,161
36
DividendsDeclaredCommonStock
TOTAL Dividends Declared-Common Stock (Acct. 438)
154,089,441
140,062,161
37
TransfersFromUnappropriatedUndistributedSubsidiaryEarnings
Transfers from Acct 216.1, Unapprop. Undistrib. Subsidiary Earnings
38
UnappropriatedRetainedEarnings
Balance - End of Period (Total 1,9,15,16,22,29,36,37)
810,816,636
769,493,168
39
AppropriatedRetainedEarningsAbstract
APPROPRIATED RETAINED EARNINGS (Account 215)
45
AppropriatedRetainedEarnings
TOTAL Appropriated Retained Earnings (Account 215)
AppropriatedRetainedEarningsAmortizationReserveFederalAbstract
APPROP. RETAINED EARNINGS - AMORT. Reserve, Federal (Account 215.1)
46
AppropriatedRetainedEarningsAmortizationReserveFederal
TOTAL Approp. Retained Earnings-Amort. Reserve, Federal (Acct. 215.1)
47
AppropriatedRetainedEarningsIncludingReserveAmortization
TOTAL Approp. Retained Earnings (Acct. 215, 215.1) (Total 45,46)
48
RetainedEarnings
TOTAL Retained Earnings (Acct. 215, 215.1, 216) (Total 38, 47) (216.1)
810,816,636
769,493,168
UnappropriatedUndistributedSubsidiaryEarningsAbstract
UNAPPROPRIATED UNDISTRIBUTED SUBSIDIARY EARNINGS (Account Report only on an Annual Basis, no Quarterly)
49
UnappropriatedUndistributedSubsidiaryEarnings
Balance-Beginning of Year (Debit or Credit)
222,330
446,074
50
EquityInEarningsOfSubsidiaryCompanies
Equity in Earnings for Year (Credit) (Account 418.1)
1,281,354
668,404
51
DividendsReceived
(Less) Dividends Received (Debit)
52
ChangesUnappropriatedUndistributedSubsidiaryEarningsCredits
TOTAL other Changes in unappropriated undistributed subsidiary earnings for the year
53
UnappropriatedUndistributedSubsidiaryEarnings
Balance-End of Year (Total lines 49 thru 52)
1,503,684
222,330


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
STATEMENT OF CASH FLOWS
  1. Codes to be used:(a) Net Proceeds or Payments;(b)Bonds, debentures and other long-term debt; (c) Include commercial paper; and (d) Identify separately such items as investments, fixed assets, intangibles, etc.
  2. Information about noncash investing and financing activities must be provided in the Notes to the Financial statements. Also provide a reconciliation between "Cash and Cash Equivalents at End of Period" with related amounts on the Balance Sheet.
  3. Operating Activities - Other: Include gains and losses pertaining to operating activities only. Gains and losses pertaining to investing and financing activities should be reported in those activities. Show in the Notes to the Financials the amounts of interest paid (net of amount capitalized) and income taxes paid.
  4. Investing Activities: Include at Other (line 31) net cash outflow to acquire other companies. Provide a reconciliation of assets acquired with liabilities assumed in the Notes to the Financial Statements. Do not include on this statement the dollar amount of leases capitalized per the USofA General Instruction 20; instead provide a reconciliation of the dollar amount of leases capitalized with the plant cost.
Line No.
Description (See Instructions No.1 for explanation of codes)
(a)
Current Year to Date Quarter/Year
(b)
Previous Year to Date Quarter/Year
(c)
1
NetCashFlowFromOperatingActivitiesAbstract
Net Cash Flow from Operating Activities
2
NetIncomeLoss
Net Income (Line 78(c) on page 117)
194,131,555
183,006,620
3
NoncashChargesCreditsToIncomeAbstract
Noncash Charges (Credits) to Income:
4
DepreciationAndDepletion
Depreciation and Depletion
179,851,232
167,041,787
5
NoncashAdjustmentsToCashFlowsFromOperatingActivities
Amortization of (Specify) (footnote details)
5.1
NoncashAdjustmentsToCashFlowsFromOperatingActivitiesDescription
Amortization of
30,981,093
28,146,754
5.2
NoncashAdjustmentsToCashFlowsFromOperatingActivitiesDescription
Other Noncash Charges to Income, Net
(a)
10,607,927
11,984,177
8
DeferredIncomeTaxesNet
Deferred Income Taxes (Net)
6,676,236
8,962,693
9
InvestmentTaxCreditAdjustmentsNet
Investment Tax Credit Adjustment (Net)
129,483
129,521
10
NetIncreaseDecreaseInReceivablesOperatingActivities
Net (Increase) Decrease in Receivables
28,520,658
38,162,608
11
NetIncreaseDecreaseInInventoryOperatingActivities
Net (Increase) Decrease in Inventory
7,177,502
26,725,059
12
NetIncreaseDecreaseInAllowancesInventoryOperatingActivities
Net (Increase) Decrease in Allowances Inventory
13
NetIncreaseDecreaseInPayablesAndAccruedExpensesOperatingActivities
Net Increase (Decrease) in Payables and Accrued Expenses
68,347,954
82,813,419
14
NetIncreaseDecreaseInOtherRegulatoryAssetsOperatingActivities
Net (Increase) Decrease in Other Regulatory Assets
36,795,341
3,473,736
15
NetIncreaseDecreaseInOtherRegulatoryLiabilitiesOperatingActivities
Net Increase (Decrease) in Other Regulatory Liabilities
19,246,127
14,255,867
16
AllowanceForOtherFundsUsedDuringConstructionOperatingActivities
(Less) Allowance for Other Funds Used During Construction
17,612,998
14,189,693
17
UndistributedEarningsFromSubsidiaryCompaniesOperatingActivities
(Less) Undistributed Earnings from Subsidiary Companies
1,281,354
668,404
18
OtherAdjustmentsToCashFlowsFromOperatingActivities
Other (provide details in footnote):
18.1
OtherAdjustmentsToCashFlowsFromOperatingActivitiesDescription
Other
(b)
79,899,767
65,963,298
22
NetCashFlowFromOperatingActivities
Net Cash Provided by (Used in) Operating Activities (Total of Lines 2 thru 21)
494,723,353
308,746,158
24
CashFlowsFromInvestmentActivitiesAbstract
Cash Flows from Investment Activities:
25
ConstructionAndAcquisitionOfPlantIncludingLandAbstract
Construction and Acquisition of Plant (including land):
26
GrossAdditionsToUtilityPlantLessNuclearFuelInvestingActivities
Gross Additions to Utility Plant (less nuclear fuel)
572,121,801
490,436,990
27
GrossAdditionsToNuclearFuelInvestingActivities
Gross Additions to Nuclear Fuel
28
GrossAdditionsToCommonUtilityPlantInvestingActivities
Gross Additions to Common Utility Plant
12,355,642
40,252,894
29
GrossAdditionsToNonutilityPlantInvestingActivities
Gross Additions to Nonutility Plant
30
AllowanceForOtherFundsUsedDuringConstructionInvestingActivities
(Less) Allowance for Other Funds Used During Construction
17,612,998
14,189,693
31
OtherConstructionAndAcquisitionOfPlantInvestmentActivities
Other (provide details in footnote):
34
CashOutflowsForPlant
Cash Outflows for Plant (Total of lines 26 thru 33)
566,864,445
516,500,191
36
AcquisitionOfOtherNoncurrentAssets
Acquisition of Other Noncurrent Assets (d)
37
ProceedsFromDisposalOfNoncurrentAssets
Proceeds from Disposal of Noncurrent Assets (d)
39
InvestmentsInAndAdvancesToAssociatedAndSubsidiaryCompanies
Investments in and Advances to Assoc. and Subsidiary Companies
40
ContributionsAndAdvancesFromAssociatedAndSubsidiaryCompanies
Contributions and Advances from Assoc. and Subsidiary Companies
41
DispositionOfInvestmentsInAndAdvancesToAssociatedAndSubsidiaryCompaniesAbstract
Disposition of Investments in (and Advances to)
42
DispositionOfInvestmentsInAndAdvancesToAssociatedAndSubsidiaryCompanies
Disposition of Investments in (and Advances to) Associated and Subsidiary Companies
44
PurchaseOfInvestmentSecurities
Purchase of Investment Securities (a)
45
ProceedsFromSalesOfInvestmentSecurities
Proceeds from Sales of Investment Securities (a)
46
LoansMadeOrPurchased
Loans Made or Purchased
47
CollectionsOnLoans
Collections on Loans
49
NetIncreaseDecreaseInReceivablesInvestingActivities
Net (Increase) Decrease in Receivables
50
NetIncreaseDecreaseInInventoryInvestingActivities
Net (Increase) Decrease in Inventory
51
NetIncreaseDecreaseInAllowancesHeldForSpeculationInvestingActivities
Net (Increase) Decrease in Allowances Held for Speculation
52
NetIncreaseDecreaseInPayablesAndAccruedExpensesInvestingActivities
Net Increase (Decrease) in Payables and Accrued Expenses
53
OtherAdjustmentsToCashFlowsFromInvestmentActivities
Other (provide details in footnote):
53.1
OtherAdjustmentsToCashFlowsFromInvestmentActivitiesDescription
Investment in Equity Securities
9,105,446
1,731,829
57
CashFlowsProvidedFromUsedInInvestmentActivities
Net Cash Provided by (Used in) Investing Activities (Total of lines 34 thru 55)
575,969,891
518,232,020
59
CashFlowsFromFinancingActivitiesAbstract
Cash Flows from Financing Activities:
60
ProceedsFromIssuanceAbstract
Proceeds from Issuance of:
61
ProceedsFromIssuanceOfLongTermDebtFinancingActivities
Long-Term Debt (b)
300,000,000
62
ProceedsFromIssuanceOfPreferredStockFinancingActivities
Preferred Stock
63
ProceedsFromIssuanceOfCommonStockFinancingActivities
Common Stock
73,612,936
276,971,002
64
OtherAdjustmentsToCashFlowsFromFinancingActivities
Other (provide details in footnote):
64.1
OtherAdjustmentsToCashFlowsFromFinancingActivitiesDescription
Treasury Stock Activity
731,249
603,028
66
NetIncreaseInShortTermDebt
Net Increase in Short-Term Debt (c)
67
OtherAdjustmentsByOutsideSourcesToCashFlowsFromFinancingActivities
Other (provide details in footnote):
67.1
DescriptionForOtherAdjustmentsByOutsideSourcesToCashFlowsFromFinancingActivities
Other
92,403
92,403
67.2
DescriptionForOtherAdjustmentsByOutsideSourcesToCashFlowsFromFinancingActivities
Line of Credit (Repayments) Borrowings, Net
70
CashProvidedByOutsideSources
Cash Provided by Outside Sources (Total 61 thru 69)
374,251,782
277,666,433
72
PaymentsForRetirementAbstract
Payments for Retirement of:
73
PaymentsForRetirementOfLongTermDebtFinancingActivities
Long-term Debt (b)
74
PaymentsForRetirementOfPreferredStockFinancingActivities
Preferred Stock
75
PaymentsForRetirementOfCommonStockFinancingActivities
Common Stock
76
OtherRetirementsOfBalancesImpactingCashFlowsFromFinancingActivities
Other (provide details in footnote):
76.1
DescriptionOfOtherRetirementsImpactingCashFlowsFromFinancingActivities
Debt Financing Costs
4,109,961
1,286,054
76.2
DescriptionOfOtherRetirementsImpactingCashFlowsFromFinancingActivities
Line of Credit (Repayments) Borrowings, Net
132,000,000
77,000,000
78
NetDecreaseInShortTermDebt
Net Decrease in Short-Term Debt (c)
80
DividendsOnPreferredStock
Dividends on Preferred Stock
81
DividendsOnCommonStock
Dividends on Common Stock
154,089,441
140,062,161
83
CashFlowsProvidedFromUsedInFinancingActivities
Net Cash Provided by (Used in) Financing Activities (Total of lines 70 thru 81)
84,052,380
213,318,218
85
NetIncreaseDecreaseInCashAndCashEquivalentsAbstract
Net Increase (Decrease) in Cash and Cash Equivalents
86
NetIncreaseDecreaseInCashAndCashEquivalents
Net Increase (Decrease) in Cash and Cash Equivalents (Total of line 22, 57 and 83)
2,805,842
3,832,356
88
CashAndCashEquivalents
Cash and Cash Equivalents at Beginning of Period
20,814,526
16,982,170
90
CashAndCashEquivalents
Cash and Cash Equivalents at End of Period
(c)
23,620,368
20,814,526


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
FOOTNOTE DATA

(a) Concept: NoncashAdjustmentsToCashFlowsFromOperatingActivities
12/31/2023 12/31/2022
Other Noncash Charges to Income, Net:
Amortization of debt issue costs, discount, and deferred hedge gain 5,500,328  6,810,280 
Gain on disposition of assets —  6,379 
Other noncash gains (54,276) (320,373)
Stock based compensation costs 5,161,875  5,487,891 
10,607,927  11,984,177 
Other Assets and Liabilities, Net:
Net change - other current assets 3,635,856  (3,322,983)
Net change - accrued utility revenues 12,308,528  (19,269,232)
Net change - deferred debits 95,975,764  (8,634,800)
Net change - deferred credits (4,972,502) (10,708,434)
Net change - noncurrent liabilities (27,047,879) (24,027,849)
79,899,767  (65,963,298)
(b) Concept: OtherAdjustmentsToCashFlowsFromOperatingActivities
Refer to footnote at column (b) line 6 for details.
(c) Concept: CashAndCashEquivalents
The following table provides a reconciliation of cash, cash equivalents, other special funds, and other special deposits reported within the Balance Sheets that sum to the total cash and cash equivalents amounts reflected in the Statement of Cash Flows:

12/31/2023 12/31/2022 12/31/2021
Cash (131) $ 8,740,865  $ 8,029,111  $ 2,300,750 
Working Funds (135) 22,850  23,450  23,250 
Special Funds (125-128) —  —  — 
Other Special Deposits (134) 14,856,653  12,761,965  14,658,170 
Total $ 23,620,368  $ 20,814,526  $ 16,982,170 

Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
NOTES TO FINANCIAL STATEMENTS
  1. Use the space below for important notes regarding the Balance Sheet, Statement of Income for the year, Statement of Retained Earnings for the year, and Statement of Cash Flows, or any account thereof. Classify the notes according to each basic statement, providing a subheading for each statement except where a note is applicable to more than one statement.
  2. Furnish particulars (details) as to any significant contingent assets or liabilities existing at end of year, including a brief explanation of any action initiated by the Internal Revenue Service involving possible assessment of additional income taxes of material amount, or of a claim for refund of income taxes of a material amount initiated by the utility. Give also a brief explanation of any dividends in arrears on cumulative preferred stock.
  3. For Account 116, Utility Plant Adjustments, explain the origin of such amount, debits and credits during the year, and plan of disposition contemplated, giving references to Commission orders or other authorizations respecting classification of amounts as plant adjustments and requirements as to disposition thereof.
  4. Where Accounts 189, Unamortized Loss on Reacquired Debt, and 257, Unamortized Gain on Reacquired Debt, are not used, give an explanation, providing the rate treatment given these items. See General Instruction 17 of the Uniform System of Accounts.
  5. Give a concise explanation of any retained earnings restrictions and state the amount of retained earnings affected by such restrictions.
  6. If the notes to financial statements relating to the respondent company appearing in the annual report to the stockholders are applicable and furnish the data required by instructions above and on pages 114-121, such notes may be included herein.
  7. For the 3Q disclosures, respondent must provide in the notes sufficient disclosures so as to make the interim information not misleading. Disclosures which would substantially duplicate the disclosures contained in the most recent FERC Annual Report may be omitted.
  8. For the 3Q disclosures, the disclosures shall be provided where events subsequent to the end of the most recent year have occurred which have a material effect on the respondent. Respondent must include in the notes significant changes since the most recently completed year in such items as: accounting principles and practices; estimates inherent in the preparation of the financial statements; status of long-term contracts; capitalization including significant new borrowings or modifications of existing financing agreements; and changes resulting from business combinations or dispositions. However were material contingencies exist, the disclosure of such matters shall be provided even though a significant change since year end may not have occurred.
  9. Finally, if the notes to the financial statements relating to the respondent appearing in the annual report to the stockholders are applicable and furnish the data required by the above instructions, such notes may be included herein.
(1)Nature of Operations and Basis of Consolidation

NorthWestern Corporation, a wholly owned subsidiary of NorthWestern Energy Group, Inc., doing business as NorthWestern Energy, provides electricity and / or natural gas to approximately 775,300 customers in Montana, South Dakota, Nebraska and Yellowstone National Park. We have generated and distributed electricity in South Dakota and distributed natural gas in South Dakota and Nebraska since 1923 and have generated and distributed electricity and distributed natural gas in Montana since 2002.

The Financial Statements for the periods included herein have been prepared by NorthWestern Corporation (NorthWestern, we or us), pursuant to the rules and regulations of the Federal Energy Regulatory Commission (FERC) as set forth in its applicable Uniform System of Accounts and published accounting releases. The preparation of financial statements in conformity with the accounting requirements of the FERC as set forth in its applicable Uniform System of Accounts and published accounting releases requires management to make estimates and assumptions that may affect the reported amounts of assets, liabilities, revenues and expenses during the reporting period. Actual results could differ from those estimates.

Events occurring subsequent to December 31, 2023, have been evaluated as to their potential impact to the Financial Statements through the date of this report.

Holding Company Reorganization

On October 2, 2023, NorthWestern Corporation and NorthWestern Energy Group, Inc. completed a merger transaction pursuant to which NorthWestern Energy Group, Inc. became the holding company parent of NorthWestern Corporation. In this reorganization, shareholders of NorthWestern Corporation (the predecessor publicly held parent company) became shareholders of NorthWestern Energy Group, Inc., maintaining the same number of shares and ownership percentage as held in NorthWestern Corporation immediately prior to the reorganization. NorthWestern Corporation became a wholly-owned subsidiary of NorthWestern Energy Group. The transaction was effected pursuant to a merger pursuant to Section 251(g) of the General Corporation Law of the State of Delaware, which provides for the formation of a holding company without a vote of the shareholders of the constituent corporation. As a result of the reorganization, NorthWestern Energy Group, Inc. became the successor issuer to NorthWestern Corporation pursuant to Rule 12g-3(a) of the Securities Exchange Act of 1934, and as a result, NorthWestern Energy Group's common stock was deemed registered under Section 12(b) of the Securities Exchange Act of 1934.

Upon the conversion of all issued and outstanding NorthWestern Corporation common stock into common stock of NorthWestern Energy Group, Inc., as described above, the common stock of NorthWestern Corporation ceased to exist. The accounting for this common stock conversion is treated as a retirement of common stock for NorthWestern Corporation as the shares cease to exist. As such, the amounts included in accounts 201 Common stock and 217 Reacquired capital stock were cleared into account 211 Other paid-in capital. Subsequent to the reorganization, NorthWestern Corporation has 100 shares of common stock issued and outstanding, which are held by NorthWestern Energy Group, Inc.

On January 1, 2024, we completed the second and final phase of the holding company reorganization. NorthWestern Corporation contributed the assets and liabilities of its South Dakota and Nebraska regulated utilities to NorthWestern Energy Public Service Corporation, and then distributed its equity interest in NorthWestern Energy Public Service Corporation and certain other subsidiaries to NorthWestern Energy Group, Inc., resulting in NorthWestern Corporation owning and operating the Montana regulated utility and NorthWestern Energy Public Service Corporation owning and operating the Nebraska and South Dakota utilities, each as a direct subsidiary of NorthWestern Energy Group, Inc.
(2)Significant Accounting Policies

Financial Statement Presentation

The financial statements are presented on the basis of the accounting requirements of the FERC as set forth in its applicable Uniform System of Accounts and published accounting releases, which is a comprehensive basis of accounting other than GAAP. This report differs from GAAP due to FERC requiring the presentation of subsidiaries on the equity method of accounting, which differs from Accounting Standards Codification (ASC) 810, Consolidation. ASC 810 requires that all majority-owned subsidiaries be consolidated (see Note 4). The other significant differences consist of the following:

Earnings per share and footnotes for revenue from contracts with customers, segment and related information, and quarterly financial data (unaudited) are not presented;
Removal and decommissioning costs of generation, transmission and distribution assets are reflected in the Balance Sheets as a component of accumulated depreciation of $523.7 million and $502.2 million as of December 31,2023 and December 31,2022, respectively, in accordance with regulatory treatment as compared to regulatory liabilities for GAAP purposes;
Goodwill is reflected in the Balance Sheets as a utility plant adjustments of $357.6 million as of December 31,2023 and December 31,2022, respectively, in accordance with regulatory treatment, as compared to goodwill for GAAP purposes (see Note 8);
The write-down of plant values associated with the 2002 acquisition of the Montana operations is reflected in the Balance Sheets as a component of accumulated depreciation of $147.6 million for December 31,2023 and December 31,2022, respectively, in accordance with regulatory treatment as compared to plant for GAAP purposes;
The current portion of gas stored underground is reflected in the Balance Sheets as current and accrued assets, as compared to inventory for GAAP purposes;
Operating lease right of use assets are reflected in the Balance Sheets as capital leases of $0.9 million and $1.3 million as of December 31,2023 and December 31,2022, respectfully, in accordance with regulatory treatment, as compared to non-current assets for GAAP purposes;
Operating lease liabilities are reflected in the Balance Sheets as current and long term obligations under capital leases of $0.9 million and $1.3 million as of December 31,2023 and December 31,2022, respectfully, in accordance with regulatory treatment, as compared to accrued expenses and long term liabilities for GAAP purposes;
Unamortized debt expense is classified in the Balance Sheets as deferred debits in accordance with regulatory treatment, as compared to long-term debt for GAAP purposes;
Current and long-term debt is classified in the Balance Sheets as all long-term debt in accordance with regulatory treatment, while current and long-term debt are presented separately for GAAP reporting;
The current portion of the provision for injuries and damages and the expected insurance proceeds receivable related to the provision for injuries and damages are reported as a current liability for GAAP purposes, as compared to a non-current liability for FERC purposes;
Accumulated deferred tax assets and liabilities are classified in the Balance Sheets as gross non-current deferred debits and credits, respectively, while GAAP presentation reflects a net non-current deferred tax liability;
Stranded tax effects associated with the Tax Cuts and Jobs Act are included in accumulated other comprehensive income (AOCI) in accordance with regulatory treatment, while included in retained earnings for GAAP purposes;
Uncertain tax positions related to temporary differences are classified in the Balance Sheets within the deferred tax accounts in accordance with regulatory treatment, as compared to other noncurrent liabilities for GAAP purposes. In addition, interest related to uncertain tax positions is recognized in interest expense in accordance with regulatory treatment, as compared to income tax expense for GAAP purposes;
Net periodic benefit costs and net periodic post retirement benefit costs are reflected in operating expense for FERC purposes, as compared to the GAAP presentation, which reflects the current service costs component of the net periodic benefit costs in operating expenses and the other components outside of income from operations. In addition, only the service cost component of net periodic benefit cost is eligible for capitalization for GAAP purposes, as compared to the total net periodic benefit costs for FERC purposes;
Regulatory assets and liabilities are reflected in the Balance Sheets as non-current items, while current and non-current amounts are presented separately for GAAP;
Unbilled revenue is reflected in the Balance Sheets in Accrued utility revenues in accordance with regulatory treatment, as compared to Accounts receivable, net for GAAP purposes;
Implementation costs associated with cloud computing arrangements are reflected on the Balance Sheets as Miscellaneous Intangible Plant in accordance with regulatory treatment, as compared to Other current assets for GAAP purposes. Additionally, these cash outflows are presented within investing activities cash outflows in the Statement of Cash Flows in accordance with regulatory treatment, as compared to operating activities cash outflows for GAAP purposes; and
GAAP revenue differs from FERC revenue primarily due to the equity method of accounting as discussed above, netting of electric purchases and sales for resale in revenue for the GAAP presentation as compared to a gross presentation for FERC purposes (with the exception of those transactions in a regional transmission organization (RTO)), the netting of RTO transmission transactions for the GAAP presentation as compared to a gross presentation for FERC purposes, and the classification of regulatory amortizations in revenue for GAAP purposes as compared to expense for FERC purposes.
The following table reconciles GAAP revenues to FERC revenues by segment for the twelve months ended December 31, 2023 and 2022 (in millions):

Twelve Months Ended December 31, 2023
TotalElectric
Natural
Gas
Other
GAAP Revenues$1,422.1 $1,068.8 $353.3 $— 
Revenue from equity investments(2.9)— (2.9)— 
Grossing revenues / power purchases93.4 93.4 — — 
Regulatory amortizations135.5 108.6 26.9 — 
Other10.6 11.3 (1.9)1.2 
FERC Revenues$1,658.7 $1,282.1 $375.4 $1.2 
Twelve Months Ended December 31, 2022
TotalElectric
Natural
Gas
Other
GAAP Revenues$1,477.8 $1,106.5 $371.3 $— 
Revenue from equity investments(3.0)— (3.0)— 
Grossing revenues / power purchases57.8 57.8 — — 
Regulatory amortizations(14.4)(44.0)29.6 — 
Other6.0 6.9 (1.9)1.0 
FERC Revenues$1,524.2 $1,127.2 $396.0 $1.0 

Use of Estimates

The preparation of financial statements in conformity with the regulatory basis of accounting requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the Financial Statements and the reported amounts of revenues and expenses during the reporting period. Estimates are used for such items as long-lived asset values and impairment charges, long-lived asset useful lives, tax provisions, uncertain tax position reserves, asset retirement obligations, regulatory assets and liabilities, allowances for uncollectible accounts, our Qualifying Facilities liability, environmental liabilities, unbilled revenues and actuarially determined benefit costs and liabilities. We revise the recorded estimates when we receive better information or when we can determine actual amounts. Those revisions can affect operating results.

Revenue Recognition

The Company recognizes revenue as customers obtain control of promised goods and services in an amount that reflects consideration expected in exchange for those goods or services. Generally, the delivery of electricity and natural gas results in the transfer of control to customers at the time the commodity is delivered and the amount of revenue recognized is equal to the amount billed to each customer, including estimated volumes delivered when billings have not yet occurred.

Cash Equivalents

We consider all highly liquid investments with maturities of three months or less at the time of purchase to be cash equivalents.

Accounts Receivable, Net

Accounts receivable are net of allowances for uncollectible accounts of $2.8 million and $2.5 million at December 31, 2023 and December 31, 2022, respectively. Unbilled revenues were $105.1 million and $117.4 million at December 31, 2023 and December 31, 2022, respectively.

Inventories

Inventories are stated at average cost. Inventory consisted of the following (in thousands):

December 31,
20232022
Fuel stock$9,711 $7,725 
Plant materials and operating supplies85,254 71,154 
Gas stored underground (including the non-current portion reflected in utility plant)55,027 63,933 
Total Inventories$149,992 $142,812 
Regulation of Utility Operations

Our regulated operations are subject to the provisions of ASC 980, Regulated Operations. Regulated accounting is appropriate provided that (i) rates are established by or subject to approval by independent, third-party regulators, (ii) rates are designed to recover the specific enterprise's cost of service, and (iii) in view of demand for service, it is reasonable to assume that rates are set at levels that will recover costs and can be charged to and collected from customers.

Our Financial Statements reflect the effects of the different rate making principles followed by the jurisdictions regulating us. The economic effects of regulation can result in regulated companies recording costs that have been, or are deemed probable to be, allowed in the ratemaking process in a period different from the period in which the costs would be charged to expense by an unregulated enterprise. When this occurs, costs are deferred as regulatory assets and recorded as expenses in the periods when those same amounts are reflected in rates. Additionally, regulators can impose liabilities upon a regulated company for amounts previously collected from customers and for amounts that are expected to be refunded to customers (Accumulated Provision for Rate Refunds).

If we were required to terminate the application of these provisions to our regulated operations, all such deferred amounts would be recognized in the Statements of Income at that time. This would result in a charge to earnings and (AOCI), net of applicable income taxes, which could be material. In addition, we would determine any impairment to the carrying costs of deregulated plant and inventory assets.

Derivative Financial Instruments

We account for derivative instruments in accordance with ASC 815, Derivatives and Hedging. All derivatives are recognized in the Balance Sheets at their fair value unless they qualify for certain exceptions, including the normal purchases and normal sales exception. Additionally, derivatives that qualify and are designated for hedge accounting are classified as either hedges of the fair value of a recognized asset or liability or of an unrecognized firm commitment (fair-value hedge) or hedges of a forecasted transaction or the variability of cash flows to be received or paid related to a recognized asset or liability (cash-flow hedge). For fair-value hedges, changes in fair values for both the derivative and the underlying hedged exposure are recognized in earnings each period. For cash-flow hedges, the portion of the derivative gain or loss that is effective in offsetting the change in the cost or value of the underlying exposure is deferred in AOCI and later reclassified into earnings when the underlying transaction occurs. Gains and losses from the ineffective portion of any hedge are recognized in earnings immediately. For other derivative contracts that do not qualify or are not designated for hedge accounting, changes in the fair value of the derivatives are recognized in earnings each period. Cash inflows and outflows related to derivative instruments are included as a component of operating, investing or financing cash flows in the Statements of Cash Flows, depending on the underlying nature of the hedged items. As of December 31, 2023, the only derivative instruments we have qualify for the normal purchases and normal sales exception.

Revenues and expenses on contracts that are designated as normal purchases and normal sales are recognized when the underlying physical transaction is completed. While these contracts are considered derivative financial instruments, they are not required to be recorded at fair value, but on an accrual basis of accounting. Normal purchases and normal sales are contracts where physical delivery is probable, quantities are expected to be used or sold in the normal course of business over a reasonable period of time, and price is not tied to an unrelated underlying derivative. As part of our regulated electric and gas operations, we enter into contracts to buy and sell energy to meet the requirements of our customers. These contracts include short-term and long-term commitments to purchase and sell energy in the retail and wholesale markets with the intent and ability to deliver or take delivery. If it were determined that a transaction designated as a normal purchase or a normal sale no longer met the exceptions, the fair value of the related contract would be reflected as an asset or liability and immediately recognized through earnings. See Note 9 - Risk Management and Hedging Activities, for further discussion of our derivative activity.

Utility Plant

Utility Plant is stated at original cost, including contracted services, direct labor and material, allowance for funds used during construction (AFUDC), and indirect charges for engineering, supervision and similar overhead items. All expenditures
for maintenance and repairs of utility plant are charged to the appropriate maintenance expense accounts. A betterment or replacement of a unit of property is accounted for as an addition and retirement of utility plant. At the time of such a retirement, the accumulated provision for depreciation is charged with the original cost of the property retired and also for the net cost of removal. Also included in plant and equipment are assets under finance lease, which are stated at the present value of minimum lease payments.

AFUDC represents the cost of financing construction projects with borrowed funds and equity funds. While cash is not realized currently from such allowance, it is realized under the ratemaking process over the service life of the related property through increased revenues resulting from a higher rate base and higher depreciation expense. The component of AFUDC attributable to borrowed funds is included as a reduction to net interest charges, while the equity component is included in other income. This rate averaged 6.4% for Montana for 2023 and 2022. This rate averaged 6.4% for South Dakota in 2023 and 2022. AFUDC capitalized totaled $24.3 million and $20.2 million for the years ended December 31, 2023 and 2022, respectively, for Montana and South Dakota combined.

We record provisions for depreciation at amounts substantially equivalent to calculations made on a straight-line method by applying various rates based on useful lives of the various classes of properties (ranging from 2 to 127 years) determined from engineering studies. As a percentage of the depreciable utility plant at the beginning of the year, our provision for depreciation of utility plant was approximately 2.8% for 2023 and 2022.

Depreciation rates include a provision for our share of the estimated costs to decommission our jointly owned plants at the end of the useful life. The annual provision for such costs is included in depreciation expense, while the accumulated provisions are included in accumulated depreciation.

Pension and Postretirement Benefits

We have liabilities under defined benefit retirement plans and a postretirement plan that offers certain health care and life insurance benefits to eligible employees and their dependents. The costs of these plans are dependent upon numerous factors, assumptions and estimates, including determination of discount rate, expected return on plan assets, rate of future compensation increases, age and mortality and employment periods. In determining the projected benefit obligations and costs, assumptions can change from period to period and may result in material changes in the cost and liabilities we recognize.

Income Taxes

We follow the liability method in accounting for income taxes. Deferred income tax assets and liabilities represent the future effects on income taxes from temporary differences between the bases of assets and liabilities for financial reporting and tax purposes. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to reverse. The probability of realizing deferred tax assets is based on forecasts of future taxable income and the availability of tax planning strategies that can be implemented, if necessary, to realize deferred tax assets. We establish a valuation allowance when it is more likely than not that all, or a portion of, a deferred tax asset will not be realized.

Exposures exist related to various tax filing positions, which may require an extended period of time to resolve and may result in income tax adjustments by taxing authorities. We have reduced deferred tax assets or established liabilities based on our best estimate of future probable adjustments related to these exposures. On a quarterly basis, we evaluate exposures in light of any additional information and make adjustments as necessary to reflect the best estimate of the future outcomes. We believe our deferred tax assets and established liabilities are appropriate for estimated exposures; however, actual results may differ from these estimates. The resolution of tax matters in a particular future period could have a material impact on our Statements of Income and provision for income taxes.

Under the Inflation Reduction Act of 2022 our production tax credits may be transferred to an unrelated entity. Our policy is to account for these transferable credits within income tax expense.
Environmental Costs

We record environmental costs when it is probable we are liable for the costs and we can reasonably estimate the liability. We may defer costs as a regulatory asset if there is precedent for recovering similar costs from customers in rates. Otherwise, we expense the costs. If an environmental cost is related to facilities we currently use, such as pollution control equipment, then we may capitalize and depreciate the costs over the remaining life of the asset, assuming the costs are recoverable in future rates or future cash flows.

Our remediation cost estimates are based on the use of an environmental consultant, our experience, our assessment of the current situation and the technology currently available for use in the remediation. We regularly adjust the recorded costs as we revise estimates and as remediation proceeds. If we are one of several designated responsible parties, then we estimate and record only our share of the cost.

Supplemental Cash Flow Information

Twelve Months Ended December 31,
20232022
(in thousands)
Cash paid (received) for:
Income taxes$(827)$4,707 
Interest105,238 95,400 
Significant non-cash transactions:
Capital expenditures included in trade accounts payable42,322 64,758 

The following table provides a reconciliation of cash, working funds, and special deposits reported within the Balance Sheets that sum to the total of the same such amounts shown in the Statements of Cash Flows (in thousands):
December 31,
20232022
Cash
$8,741 $8,029 
Working funds
23 23 
Special deposits
14,857 12,762 
Total shown in the Statement of Cash Flows
$23,621 $20,814 

Special deposits consist primarily of funds held in trust accounts to satisfy the requirements of certain stipulation agreements and insurance reserve requirements.

Accounting Standards Issued

There were no accounting standards adopted in the current year that had a material impact to our financial condition, results of operations, and cash flows. At this time, we are not expecting the adoption of recently issued accounting standards to have a material impact to our financial condition, results of operations, and cash flows.
(3)Regulatory Matters

Montana Rate Review

On August 8, 2022, we filed a Montana electric and natural gas rate review with the MPSC under Docket 2022.07.78 requesting an annual increase to electric and natural gas utility rates. On October 27, 2023, the MPSC issued a final order approving the settlement agreement filed April 3, 2023. Final rates, adjusting from interim to settled rates, were effective November 1, 2023. The details of our settlement agreement are set forth below:

Returns, Capital Structure & Revenue Increase Resulting From Approved Settlement Agreement ($ in millions)
ElectricNatural Gas
Return on Equity (ROE)9.65%9.55%
Equity Capital Structure48.02%48.02%
Base Rates$67.4$14.1
PCCAM(1)
$69.7n/a
Property Tax (tracker base adjustment)(1)
$14.5$4.2
Total Revenue Increase Through Approved Settlement Agreement$151.6$18.3
(1) These items are flow-through costs. PCCAM reflects our fuel and purchased power costs.

The approved settlement includes, among other things, agreement on electric and natural gas base revenue increases, allocated cost of service, rate design, updates to the base amount of revenues associated with property taxes and electric supply costs, and regulatory policy issues related to requested changes in regulatory mechanisms.

The approved settlement agreement provides for an update to the PCCAM by adjusting the base costs from $138.7 million to $208.4 million and providing for more timely quarterly recovery of deferred balances instead of annual recovery. It also addresses the potential for future recovery of certain operating costs associated with the Yellowstone County Generating Station and provides for the deferral of incremental operating costs related to our Enhanced Wildfire Mitigation Plan. The settling parties agreed to terminate the pilot decoupling program (Fixed Cost Recovery Mechanism) and that the proposed business technology rider will not be implemented.

South Dakota Electric Rate Review

On June 15, 2023, we filed a South Dakota electric rate review filing (2022 test year) under Docket EL23-016 for an annual increase to electric rates totaling approximately $30.9 million. Our request was based on a rate of return of 7.54 percent, a capital structure including 50.5 percent equity, and rate base of $787.3 million. On January 10, 2024, the SDPUC issued a final order approving the settlement agreement between NorthWestern and SDPUC Staff for an annual increase in base rates of approximately $21.5 million and an authorized rate of return of 6.81 percent. The approved settlement is based on a capital structure of 50.5 percent equity and a rate base of $791.8 million. Final rates were effective January 10, 2024. In addition, NorthWestern was approved a phase in rate plan rider that allows for the recovery of capital investments not yet included in base rates.
(4)Equity Investments

The following table presents our equity investments reflected in the investments in subsidiary companies on the Balance Sheets (in thousands):

December 31,
2023

2022
Havre Pipeline Company, LLC$13,163 

$11,399 
NorthWestern Energy Solutions, Inc.11,797 5,738 
Canadian Montana Pipeline Corporation5,182 4,984 
NorthWestern Services, LLC2,135 2,091 
Risk Partners Assurance, Ltd.1,097 1,132 
NorthWestern Energy Public Service Corporation— 
Total Investments in Subsidiary Companies$33,374 $25,344 
(5)Regulatory Assets and Liabilities
We prepare our Financial Statements in accordance with the provisions of ASC 980, as discussed in Note 2 - Significant Accounting Policies. Pursuant to this guidance, certain expenses and credits, normally reflected in income as incurred, are deferred and recognized when included in rates and recovered from or refunded to customers. Regulatory assets and liabilities are recorded based on management's assessment that it is probable that a cost will be recovered or that an obligation has been incurred. Accordingly, we have recorded the following major classifications of regulatory assets and liabilities that will be recognized in expenses and revenues in future periods when the matching revenues are collected or refunded. Of these regulatory assets and liabilities, energy supply costs are the only items earning a rate of return. These remaining regulatory items have corresponding assets and liabilities that will be paid for or refunded in future periods.

Note Reference
Remaining Amortization Period
December 31,


20232022
(in thousands)
Flow-through income taxes14Plant Lives$553,452 $509,038 
Pension16See Note 1679,638 87,965 
Excess deferred income taxes14Plant Lives51,404 54,364 
Employee related benefits16See Note 1621,926 27,920 
State & local taxes & fees1 Year2,733 15,643 
Environmental clean-up19Undetermined11,131 10,963 
OtherVarious25,741 23,191 
Total Regulatory Assets
$746,025 $729,084 
Excess deferred income taxes14Plant Lives136,382 148,989 
Unbilled revenue1 Year16,004 11,536 
Gas storage sales17 years6,625 7,046 
State & local taxes & fees1 Year30,576 2,327 
Environmental clean-up and other1 Year1,059 1,503 
Total Regulatory Liabilities
$190,646 $171,401 

Income Taxes

Flow-through income taxes primarily reflect the effects of plant related temporary differences such as flow-through of depreciation, repairs related deductions, and removal costs that we will recover or refund in future rates. We amortize these amounts as temporary differences reverse. Excess deferred income tax assets and liabilities are recorded as a result of the Tax Cuts and Jobs Act and will be recovered or refunded in future rates. See Note 14 - Income Taxes for further discussion.

Pension and Employee Related Benefits

We recognize the unfunded portion of plan benefit obligations in the Balance Sheets, which is remeasured at each year end, with a corresponding adjustment to regulatory assets/liabilities as the costs associated with these plans are recovered in rates. The MPSC allows recovery of pension costs on a cash funding basis. The portion of the regulatory asset related to our Montana pension plan will amortize as cash funding amounts exceed accrual expense under GAAP. The SDPUC allows recovery of pension and postretirement benefit costs on an accrual basis. The MPSC allows recovery of postretirement benefit costs on an accrual basis.

State & Local Taxes & Fees (Montana Property Tax Tracker)
Under Montana law, we are allowed to track the changes in the actual level of state and local taxes and fees and recover the increase in rates, less the amount allocated to FERC jurisdictional customers and net of the related income tax benefit.

Environmental Clean-up

Environmental clean-up costs are the estimated costs of investigating and cleaning up contaminated sites we own. We discuss the specific sites and clean-up requirements further in Note 19 - Commitments and Contingencies. Environmental clean-up costs are typically recoverable in customer rates when they are actually incurred. When cost projections become known and measurable, we coordinate with the appropriate regulatory authority to determine a recovery period.

Gas Storage Sales

A regulatory liability was established in 2000 and 2001 based on gains on cushion gas sales in Montana. This gain is being flowed to customers over a period that matches the depreciable life of surface facilities that were added to maintain deliverability from the field after the withdrawal of the gas. This regulatory liability is a reduction of rate base.

Enhanced Wildfire Mitigation Plan

We have developed an Enhanced Wildfire Mitigation Plan addressing five key areas: situational awareness, operational practices, system preparedness, vegetation management, and public communications outreach. Because of ever-increasing wildfire risk, our plan includes greater focus on situational awareness to monitor changing environmental conditions, operational practices that are more reactive to changing conditions, increased frequency of patrol and repairs, and more robust system hardening programs that target higher risk segments in our transmission and distribution systems. As discussed within Note 3 - Regulatory Matters, the approved Montana rate review settlement provides for the deferral of incremental operating costs related to this Enhanced Wildfire Mitigation Plan. As of December 31, 2023, we have deferred $1.6 million of incremental costs as a regulatory asset related to this plan for future recovery.

Unbilled Revenue

In accordance with regulatory guidance in South Dakota, we recognize revenue when it is billed. Accordingly, we record a regulatory liability to offset unbilled revenue.
(6)Utility Plant

The following table presents the major classifications of our net utility plant (in thousands):
December 31,
2023

2022
(in thousands)
Electric Plant$5,543,091 $5,286,650 
Natural Gas Plant1,446,664 1,311,436 
Plant acquisition adjustment686,328 686,328 
Common and Other Plant307,030 306,866 
Construction work in process358,401 300,649 
Total utility plant8,341,514 7,891,929 
Less accumulated depreciation(2,874,902)(2,786,712)
Net utility plant$5,466,612 $5,105,217 
Net utility plant under capital (finance) lease were $5.2 million and $7.2 million as of December 31, 2023 and 2022, respectively, which included $5.0 million and $7.0 million as of December 31, 2023 and 2022, respectively, related to a long-term power supply contract with the owners of a natural gas fired peaking plant, which has been accounted for as a finance lease.

Jointly Owned Electric Generating Plant

We have an ownership interest in four base-load electric generating plants, all of which are coal fired and operated by other companies. We have an undivided interest in these facilities and are responsible for our proportionate share of the capital and operating costs while being entitled to our proportionate share of the power generated. Our interest in each plant is reflected in the Balance Sheets on a pro rata basis and our share of operating expenses is reflected in the Statements of Income. The participants each finance their own investment.

On January 16, 2023, we entered into a definitive agreement (Agreement) with Avista Corporation (Avista) to acquire Avista's 15 percent interest in each of Units 3 and 4 at the Colstrip Generating Station, a coal-fired, base-load electric generation facility located in Colstrip, Montana. As noted in the table below, we currently have a 30 percent interest in Unit 4. The Agreement provides that the purchase price will be $0 and that we will acquire Avista's interest effective December 31, 2025, subject to the satisfaction of the closing conditions contained within the agreement. Under the terms of this Agreement, we will be responsible for operating costs starting on January 1, 2026; while Avista will retain responsibility for its pre-closing share of environmental and pension liabilities attributed to events or conditions existing prior to the closing of the transaction and for any future decommission and demolition costs associated with the existing facilities that comprise Avista's interest.

The Agreement contains customary representations and warranties, covenants, and indemnification obligations, and the Agreement is subject to customary conditions and approvals, including approval from the FERC. Closing also is conditioned on our ability to enter into a new coal supply agreement for Colstrip by December 31, 2024. Such coal supply agreement must provide a sufficient amount of coal to Colstrip to permit the generation of electric power by the maximum permitted capacity of the interest in Colstrip then held by us during the period from January 1, 2026 through, December 31, 2030.

Either party may terminate the Agreement if any requested regulatory approval is denied or if the closing has not occurred by December 31, 2025 or if any law or order would delay or impair closing.

Information relating to our ownership interest in these facilities is as follows (in thousands):

Big Stone
(SD)
Neal #4
(IA)
Coyote
(ND)
Colstrip Unit 4 (MT)
December 31,2023
Ownership percentages
23.4 %8.7 %10.0 %30.0 %
Plant in service
$156,696 $64,132 $52,630 $323,793 
Accumulated depreciation
48,537 40,528 42,942 128,484 
December 31,2022
Ownership percentages
23.4 %8.7 %10.0 %30.0 %
Plant in service
$155,567 $63,032 $51,796 $326,584 
Accumulated depreciation
46,748 39,077 42,465 122,938 
(7)Asset Retirement Obligations
We are obligated to dispose of certain long-lived assets upon their abandonment. We recognize a liability for the legal obligation to perform an asset retirement activity in which the timing and/or method of settlement are conditional on a future event. We measure the liability at fair value when incurred and capitalize a corresponding amount as part of the book value of the related assets, which increases our utility plant and asset retirement obligations (ARO). The increase in the capitalized cost is included in determining depreciation expense over the estimated useful life of these assets. Since the fair value of the ARO is determined using a present value approach, accretion of the liability due to the passage of time is recognized each period and recorded as a regulatory asset until the settlement of the liability. Revisions to estimated AROs can result from changes in retirement cost estimates, revisions to estimated inflation rates, and changes in the estimated timing of abandonment. If the obligation is settled for an amount other than the carrying amount of the liability, we will recognize a regulatory asset or liability for the difference, which will be surcharged/refunded to customers through the rate making process. We record regulatory assets and liabilities for differences in timing of asset retirement costs recovered in rates and AROs recorded since asset retirement costs are recovered through rates charged to customers.

Our AROs relate to the reclamation and removal costs at our jointly-owned coal-fired generation facilities, U.S. Department of Transportation requirements to cut, purge and cap retired natural gas pipeline segments, our obligation to plug and abandon oil and gas wells at the end of their life, and to remove all above-ground wind power facilities and restore the soil surface at the end of their life. The following table presents the change in our ARO (in thousands):

December 31,
2023

2022
Liability at January 1,
$40,894 $40,631 
Accretion expense
1,899 1,853 
Liabilities incurred
— — 
Liabilities settled
(1,244)(4,004)
Revisions to cash flows
(125)2,414 
Liability at December 31,
$41,424 $40,894 

During the twelve months ended December 31, 2023 our ARO liability decreased $1.2 million for partial settlement of the legal obligations at our jointly-owned coal-fired generation facilities and natural gas pipeline segments. Additionally, during the twelve months ended December 31, 2023, our ARO liability decreased $0.1 million related to changes in both the timing and amount of retirement cost estimates.

In addition, we have identified removal liabilities related to our electric and natural gas transmission and distribution assets that have been installed on easements over property not owned by us. The easements are generally perpetual and only require remediation action upon abandonment or cessation of use of the property for the specified purpose. The ARO liability is not estimable for such easements as we intend to utilize these properties indefinitely. In the event we decide to abandon or cease the use of a particular easement, an ARO liability would be recorded at that time. We also identified AROs associated with our hydroelectric generating facilities; however, due to the indeterminate removal date, the fair value of the associated liabilities currently cannot be estimated and no amounts are recognized in the Financial Statements.

We collect removal costs in rates for certain transmission and distribution assets that do not have associated AROs. Generally, the accrual of future non-ARO removal obligations is not required; however, long-standing ratemaking practices approved by applicable state and federal regulatory commissions have allowed provisions for such costs in historical depreciation rates.
(8)Utility Plant Adjustments

We completed our annual utility plant adjustment impairment test as of April 1, 2023. We evaluated qualitative factors (including macroeconomic conditions, industry and market considerations, cost factors, and overall financial performance) to determine whether it was more likely than not that the fair value of our reporting units were less than their carrying amounts. Our evaluation of these factors concluded that it was not more likely than not that the fair value of our reporting units was less than their carrying amounts and therefore no further testing was necessary.
(9)Risk Management and Hedging Activities

Nature of Our Business and Associated Risks

We are exposed to certain risks related to the ongoing operations of our business, including the impact of market fluctuations in the price of electricity and natural gas commodities and changes in interest rates. We rely on market purchases to fulfill a portion of our electric and natural gas supply requirements. Several factors influence price levels and volatility. These factors include, but are not limited to, seasonal changes in demand, weather conditions, available generating assets within regions, transportation availability and reliability within and between regions, fuel availability, market liquidity, and the nature and extent of current and potential federal and state regulations.

Objectives and Strategies for Using Derivatives

To manage our exposure to fluctuations in commodity prices we routinely enter into derivative contracts. These types of contracts are included in our electric and natural gas supply portfolios and are used to manage price volatility risk by taking advantage of fluctuations in market prices. While individual contracts may be above or below market value, the overall portfolio approach is intended to provide greater price stability for consumers. We do not maintain a trading portfolio, and our derivative transactions are only used for risk management purposes consistent with regulatory guidelines.

In addition, we may use interest rate swaps to manage our interest rate exposures associated with new debt issuances or to manage our exposure to fluctuations in interest rates on variable rate debt.

Accounting for Derivative Instruments

We evaluate new and existing transactions and agreements to determine whether they are derivatives. The permitted accounting treatments include: normal purchase normal sale (NPNS); cash flow hedge; fair value hedge; and mark-to-market.
Mark-to-market accounting is the default accounting treatment for all derivatives unless they qualify, and we specifically designate them, for one of the other accounting treatments. Derivatives designated for any of the elective accounting treatments must meet specific, restrictive criteria both at the time of designation and on an ongoing basis. The changes in the fair value of recognized derivatives are recorded each period in current earnings or other comprehensive income, depending on whether a derivative is designated as part of a hedge transaction and the type of hedge transaction.

Normal Purchases and Normal Sales

We have applied the NPNS scope exception to our contracts involving the physical purchase and sale of gas and electricity at fixed prices in future periods. During our normal course of business, we enter into full-requirement energy contracts, power purchase agreements and physical capacity contracts, which qualify for NPNS. All of these contracts are accounted for using the accrual method of accounting; therefore, there were no unrealized amounts recorded in the Financial Statements at December 31, 2023 and 2022. Revenues and expenses from these contracts are reported on a gross basis in the appropriate revenue and expense categories as the commodities are received or delivered.

Credit Risk

Credit risk is the potential loss resulting from counterparty non-performance under an agreement. We manage credit risk with policies and procedures for, among other things, counterparty analysis and exposure measurement, monitoring and mitigation. We limit credit risk in our commodity and interest rate derivatives activities by assessing the creditworthiness of potential counterparties before entering into transactions with them and continuing to evaluate their creditworthiness on an ongoing basis.

We are exposed to credit risk through buying and selling electricity and natural gas to serve customers. We may request collateral or other security from our counterparties based on the assessment of creditworthiness and expected credit exposure. It is possible that volatility in commodity prices could cause us to have material credit risk exposures with one or more counterparties. We enter into commodity master enabling agreements with our counterparties to mitigate credit exposure, as
these agreements reduce the risk of default by allowing us or our counterparty the ability to make net payments. The agreements generally are: (1) Western Systems Power Pool agreements – standardized power purchase and sales contracts in the electric industry; (2) International Swaps and Derivatives Association agreements – standardized financial gas and electric contracts; (3) North American Energy Standards Board agreements – standardized physical gas contracts; and (4) Edison Electric Institute Master Purchase and Sale Agreements – standardized power sales contracts in the electric industry.

Many of our forward purchase contracts contain provisions that require us to maintain an investment grade credit rating from each of the major credit rating agencies. If our credit rating were to fall below investment grade, the counterparties could require immediate payment or demand immediate and ongoing full overnight collateralization on contracts in net liability positions.

Interest Rate Swaps Designated as Cash Flow Hedges

We have previously used interest rate swaps designated as cash flow hedges to manage our interest rate exposures associated with new debt issuances. We have no interest rate swaps outstanding. These swaps were designated as cash flow hedges with the effective portion of gains and losses, net of associated deferred income tax effects, recorded in AOCI. We reclassify these gains from AOCI into interest on long term debt during the periods in which the hedged interest payments occur. The following table shows the effect of these interest rate swaps previously terminated on the Financial Statements (in thousands):
Cash Flow HedgesLocation of Amount Reclassified from AOCI to IncomeAmount Reclassified from AOCI into Income during the Year Ended December 31, 2021
Interest rate contracts
Interest on long-term debt
$612 

A pre-tax loss of approximately $12.8 million is remaining in AOCI as of December 31, 2023, and we expect to reclassify approximately $0.6 million of pre-tax losses from AOCI into interest expense during the next twelve months. These amounts relate to terminated swaps.
(10)Fair Value Measurements

Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (i.e., an exit price). Measuring fair value requires the use of market data or assumptions that market participants would use in pricing the asset or liability, including assumptions about risk and the risks inherent in the inputs to the valuation technique. These inputs can be readily observable, corroborated by market data, or generally unobservable. Valuation techniques are required to maximize the use of observable inputs and minimize the use of unobservable inputs.

Applicable accounting guidance establishes a hierarchy that prioritizes the inputs used to measure fair value, and requires fair value measurements to be categorized based on the observability of those inputs. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 inputs) and the lowest priority to unobservable inputs (Level 3 inputs). The three levels of the fair value hierarchy are as follows:

Level 1 – Unadjusted quoted prices available in active markets at the measurement date for identical assets or liabilities;
Level 2 – Pricing inputs, other than quoted prices included within Level 1, which are either directly or indirectly observable as of the reporting date; and
Level 3 – Significant inputs that are generally not observable from market activity.
We classify assets and liabilities within the fair value hierarchy based on the lowest level of input that is significant to the fair value measurement of each individual asset and liability taken as a whole. Due to the short-term nature of cash and cash equivalents, accounts receivable, net, and accounts payable, the carrying amount of each such item approximates fair value. The table below sets forth by level within the fair value hierarchy the gross components of our assets and liabilities measured at fair value on a recurring basis. NPNS transactions are not included in the fair values by source table as they are not recorded at fair value. See Note 9 - Risk Management and Hedging Activities for further discussion.

We record transfers between levels of the fair value hierarchy, if necessary, at the end of the reporting period. There were no transfers between levels for the periods presented.

December 31,2023Quoted Prices in Active Markets for Identical Assets or Liabilities (Level 1)Significant Other Observable Inputs (Level 2)Significant Unobservable Inputs (Level 3)Margin Cash Collateral OffsetTotal Net Fair Value
(in thousands)
Special deposits$14,857 $— $— $— $14,857 
Rabbi trust investments17,093 — — — 17,093 
Total$31,950 $ $ $ $31,950 
December 31,2022
Special deposits$12,762 $— $— $— $12,762 
Rabbi trust investments20,895 — — — 20,895 
Total$33,657 $ $ $ $33,657 

Special deposits represent amounts held in money market mutual funds. Rabbi trust investments represent assets held for non-qualified deferred compensation plans, which consist of our common stock and actively traded mutual funds with quoted prices in active markets.

Financial Instruments

The estimated fair value of financial instruments is summarized as follows (in thousands):

December 31,2023December 31, 2022
Carrying AmountFair ValueCarrying AmountFair Value
Liabilities:
Long-term debt$2,797,660 $2,534,105 $2,629,660 $2,327,478 

The estimated fair value amounts have been determined using available market information and appropriate valuation methodologies; however, considerable judgment is required in interpreting market data to develop estimates of fair value. Accordingly, the estimates presented herein are not necessarily indicative of the amounts that we would realize in a current market exchange.

We determined fair value for long-term debt based on interest rates that are currently available to us for issuance of debt with similar terms and remaining maturities, except for publicly traded debt, for which fair value is based on market prices for the same or similar issues or upon the quoted market prices of U.S. treasury issues having a similar term to maturity, adjusted for our bond issuance rating and the present value of future cash flows. These are significant other observable inputs, or level 2 inputs, in the fair value hierarchy.
(11)Unsecured Credit Facilities

Credit Facility

On November 29, 2023, NorthWestern Corporation amended its existing $425.0 million revolving credit facility (the Amended Facility) to address the holding company reorganization and extended the maturity date of the facility to November 29, 2028. The Amended Facility does not amortize and is unsecured. Borrowings may be made at interest rates equal to (a) SOFR, plus a credit spread adjustment of 10.0 basis points plus a margin of 100.0 to 175.0 basis points, or (b) a base rate, plus a margin of 0.0 to 75.0 basis points. After the completion of the holding company reorganization on January 1, 2024, NorthWestern Corporation owns and operates only the Montana regulated utility, and the base capacity of the Amended Facility automatically reduced to $400.0 million.

On October 28, 2022, we entered into a $100.0 million Credit Agreement (the Additional Credit Facility) to supplement our existing $425.0 million revolving credit facility. The Additional Credit Facility has a maturity date of April 28, 2024. The Additional Credit Facility does not amortize and is unsecured. Borrowings may be made at interest rates equal to (a) SOFR, plus a credit spread adjustment of 10.0 basis points, plus a margin of 100.0 to 175.0 basis points, or (b) a base rate, plus a margin of 0.0 to 75.0 basis points. As of December 31, 2023, there were no amounts outstanding under this Additional Credit Facility.

On March 25, 2023, we amended our existing $25.0 million swingline credit facility (the Swingline Facility) to extend the maturity date of the facility from March 27, 2024 to March 27, 2025. The Swingline Facility does not amortize and is unsecured. Borrowings may be made at interest rates equal to (a) SOFR, plus a margin of 90.0 basis points, or (b) a base rate, plus a margin of 12.5 basis points. As of December 31, 2023, there were no amounts outstanding under this Swingline Facility.

On January 2, 2024, NorthWestern Corporation terminated its $100.0 million Additional Credit Facility. On January 4, 2024, NorthWestern Corporation terminated its $25.0 million Swingline Facility.

Commitment fees for the unsecured revolving lines of credit were $0.6 million and $0.1 million for the years ended December 31, 2023 and 2022.

The availability under the facilities in place for the years ended December 31 is shown in the following table (in millions):

2023

2022
Unsecured revolving line of credit, expiring May 2027$— $425.0 
Unsecured revolving line of credit, expiring November 2028(1)
425.0 — 
Unsecured revolving line of credit, expiring April 2024(2)
100.0 100.0 
Unsecured revolving line of credit, expiring March 2025(2)
25.0 25.0 

550.0 550.0 

Amounts outstanding at December 31:
SOFR borrowings318.0 450.0 
Letters of credit— — 
318.0 450.0 
Net availability as of December 31$232.0 $100.0 
(1) Upon the completion of the holding company reorganization on January 1, 2024, the base capacity of this facility decreased to $400.0 million.
(2) NorthWestern Corporation terminated the $100.0 million Additional Credit Facility on January 2, 2024, and the $25.0 million Swingline Facility on January 4, 2024.
Our credit facilities include covenants that require us to meet certain financial tests, including a maximum debt to capitalization ratio not to exceed 65 percent. The facilities also contain covenants which, among other things, limit our ability to engage in any consolidation or merger or otherwise liquidate or dissolve, dispose of property, and enter into transactions with affiliates. A default on the Montana First Mortgage Bonds would trigger a cross default on the Amended Facility; however, a default on the Amended Facility would not trigger a default on the Montana First Mortgage Bonds.
(12)Long-Term Debt

Long-term debt consisted of the following (in thousands):
December 31,

Due
2023

2022
Unsecured Debt:

Unsecured Revolving Line of Credit2027$— $425,000 
Unsecured Revolving Line of Credit2028318,000 — 
Unsecured Revolving Line of Credit2024— 25,000 
Secured Debt:
Mortgage bonds—
South Dakota—5.01%202564,000 64,000 
South Dakota—4.15%204230,000 30,000 
South Dakota—4.30%205220,000 20,000 
South Dakota—4.85%204350,000 50,000 
South Dakota—4.22%204430,000 30,000 
South Dakota—4.26%204070,000 70,000 
South Dakota—3.21%203050,000 50,000 
South Dakota—2.80%202660,000 60,000 
South Dakota—2.66%202645,000 45,000 
South Dakota—5.57%203331,000 — 
South Dakota—5.42%203330,000 — 
Montana—5.71%203955,000 55,000 
Montana—5.01%2025161,000 161,000 
Montana—4.15%204260,000 60,000 
Montana—4.30%205240,000 40,000 
Montana—4.85%204315,000 15,000 
Montana—3.99%202835,000 35,000 
Montana—4.176%2044450,000 450,000 
Montana—3.11%202575,000 75,000 
Montana—4.11%2045125,000 125,000 
Montana—4.03%2047250,000 250,000 
Montana—3.98%2049150,000 150,000 
Montana—3.21%2030100,000 100,000 
Montana—1.00%2024100,000 100,000 
Montana—5.57%2033239,000 — 
Pollution control obligations—
Montana—2.00%2023— 144,660 
Montana—3.88%2028144,660 — 
Total Long-Term Debt$2,797,660 $2,629,660 

Secured Debt

First Mortgage Bonds and Pollution Control Obligations

The South Dakota First Mortgage Bonds are a series of general obligation bonds issued under our South Dakota indenture. These bonds are secured by substantially all of our South Dakota and Nebraska electric and natural gas assets. The South Dakota indenture was transferred from NorthWestern Corporation to NorthWestern Energy Public Service Corporation upon the completion of the holding company reorganization on January 1, 2024.
The Montana First Mortgage Bonds are a series of general obligation bonds issued under our Montana indenture. These bonds are secured by substantially all of our Montana electric and natural gas assets.

On March 30, 2023, we issued and sold $239.0 million aggregate principal amount of Montana First Mortgage Bonds (the bonds) at a fixed interest rate of 5.57 percent maturing on March 30, 2033. On this same day, we issued and sold $31.0 million aggregate principal amount of South Dakota First Mortgage Bonds at a fixed interest rate of 5.57 percent maturing on March 30, 2033. On May 1, 2023, we issued and sold an additional $30 million aggregate principal amount of South Dakota First Mortgage Bonds at a fixed interest rate of 5.42 percent maturing on May 1, 2033. These bonds were issued in transactions exempt from the registration requirements of the Securities Act of 1933. Proceeds were used to repay a portion of our outstanding borrowings under our revolving credit facilities and for other general corporate purposes.

On June 29, 2023, the City of Forsyth, Rosebud County, Montana issued $144.7 million principal amount of Pollution Control Revenue Refunding Bonds (2023 Pollution Control Bonds) on our behalf. The 2023 Pollution Control Bonds were issued at a fixed interest rate of 3.88 percent maturing on July 1, 2028. The proceeds of the issuance were loaned to us pursuant to a Loan Agreement and were deposited directly with U.S. Bank Trust Company, National Association, as trustee, for the redemption of the 2.00 percent, $144.7 million City of Forsyth Pollution Control Revenue Refunding Bonds due on August 1, 2023 that had previously been issued on our behalf. Pursuant to the Loan Agreement, we are obligated to make payments in such amounts and at such times as will be sufficient to pay, when due, the principal and interest on the 2023 Pollution Control Bonds. Our obligations under the Loan Agreement are secured by delivery of a like amount of our Montana First Mortgage Bonds, which are secured by our Montana electric and natural gas assets. So long as we are making payments under the Loan Agreement, no payments under these mortgage bonds will be due. The 2023 Pollution Control Bonds were issued in a transaction exempt from the registration requirements of the Securities Act of 1933, as amended.

As of December 31, 2023, we were in compliance with our financial debt covenants.

Maturities of Long-Term Debt

The aggregate minimum principal maturities of long-term debt during the next five years are $100.0 million in 2024, $300.0 million in 2025, $105.0 million in 2026, and $497.7 million in 2028.
(13)Related Party Transactions

Accounts receivable from and payables to associated companies primarily include intercompany billings for direct charges, overhead, and income tax obligations. The following table reflects our accounts receivable from and accounts payable to associated companies (in thousands):

December 31,

2023

2022
Accounts Receivable from Associated Companies:

Havre Pipeline Company, LLC$591 $3,201 
NorthWestern Energy Solutions, Inc.112 16 
Risk Partners Assurance, Ltd.(88)(74)
$615 $3,143 
Accounts Payable to Associated Companies:
Canadian Montana Pipeline Corporation$2,516 $2,312 
NorthWestern Services, LLC2,082 2,045 
NorthWestern Energy Group, Inc.206 — 
$4,804 $4,357 
(14)Income Taxes

Our effective tax rate typically differs from the federal statutory tax rate primarily due to production tax credits and the regulatory impact of flowing through the federal and state tax benefit of repairs deductions, state tax benefit of accelerated tax depreciation deductions (including bonus depreciation when applicable), and production tax credits. The regulatory accounting treatment of these deductions requires immediate income recognition for temporary tax differences of this type, which is referred to as the flow-through method. When the flow-through method of accounting for temporary differences is reflected in regulated revenues, we record deferred income taxes and establish related regulatory assets and liabilities.

The components of the net deferred income tax liability recognized in our Balance Sheets are related to the following temporary differences (in thousands):

December 31,

2023

2022
NOL Carryforward$113,310 $— 
Production tax credit94,283 80,097 
Pension / postretirement benefits15,131 19,291 
Customer advances28,300 25,119 
Unbilled revenue10,604 9,440 
Compensation accruals10,716 10,306 
Environmental liability5,760 6,009 
Interest rate hedges3,280 3,372 
Reserves and accruals3,098 4,015 
Other, net5,401 6,295 
Deferred Tax Asset289,883 163,944 
Excess tax depreciation(663,638)(455,220)
Flow through depreciation(119,458)(104,976)
Goodwill amortization(91,803)(91,746)
Regulatory assets and other(20,246)(58,065)
Deferred Tax Liability(895,145)(710,007)
Deferred Tax Liability, net$(605,262)$(546,063)

As of December 31, 2023, our total federal NOL carryforward was approximately $447.8 million. Our federal NOL carryforward does not expire. Our state NOL carryforward as of December 31, 2023 was approximately $362.1 million. If unused, our state NOL carryforwards will expire in 2033. We believe it is more likely than not that sufficient taxable income will be generated to utilize these NOL carryforwards.

At December 31, 2023, our total production tax credit carryforward was approximately $94.3 million. If unused, our production tax credit carryforwards will expire as follows: $1.8 million in 2035, $10.9 million in 2036, $11.1 million in 2037, $10.9 million in 2038, $11.5 million in 2039, $13.1 million in 2040, $11.5 million in 2041, $13.2 million in 2042, and $10.4 million in 2043. We believe it is more likely than not that sufficient taxable income will be generated to utilize these production tax credit carryforwards.

Uncertain Tax Positions
We recognize tax positions that meet the more-likely-than-not threshold as the largest amount of tax benefit that is greater than 50 percent likely of being realized upon ultimate settlement with a taxing authority that has full knowledge of all relevant information. The change in unrecognized tax benefits is as follows (in thousands):


2023

2022
Unrecognized Tax Benefits at January 1$30,330 $32,049 
Gross increases - tax positions in prior period— — 
Gross increases - tax positions in current period— — 
Gross decreases - tax positions in current period(2,256)(1,719)
Lapse of statute of limitations— — 
Unrecognized Tax Benefits at December 31$28,074 $30,330 

Our unrecognized tax benefits include approximately $24.4 million and $27.9 million related to tax positions as of December 31, 2023 and 2022, that if recognized, would impact our annual effective tax rate. On April 14, 2023, the Internal Revenue Service (IRS) issued Revenue Procedure 2023-15, which provides a safe harbor method of accounting for gas repairs expenditures. During the year ended December 31, 2023, we adopted this method and decreased our total unrecognized tax benefits by $0.5 million and recognized an income tax benefit of approximately $3.2 million for previously unrecognized tax benefits. In the next twelve months we expect the statute of limitations to expire for certain uncertain tax benefits, which would result in a decrease to our total unrecognized tax benefits of approximately $16.9 million.

Our policy is to recognize interest related to uncertain tax positions in interest expense. As of December 31, 2023, we have accrued $4.5 million for the payment of interest in the Balance Sheets. As of December 31, 2022, we had $1.4 million accrued for the payment of interest.

Tax years 2020 and forward remain subject to examination by the IRS and state taxing authorities. During the first quarter of 2023 the IRS commenced and concluded a limited scope examination of our 2019 amended federal income tax return. This examination resulted in a reduction to our previously claimed alternative minimum tax credit refund that is reflected in the table above.
(15)Comprehensive Income (Loss)

The following tables display the components of Other Comprehensive Income (Loss), after-tax, and the related tax effects (in thousands):

December 31,
20232022
Before-
Tax Amount
Tax
Expense (Benefit)
Net-of-
Tax Amount
Before-
Tax Amount
Tax
Expense (Benefit)
Net-of-
Tax Amount
Foreign currency translation adjustment$$— $$(8)$— $(8)
Reclassification of net income (loss) on derivative instruments612 (160)452 612 (160)452 
Postretirement medical liability adjustment(330)69 (261)(1,359)377 (982)
Other comprehensive income (loss)$284 $(91)$193 $(755)$217 $(538)
Balances by classification included within AOCI on the Balance Sheets are as follows, net of tax (in thousands):

December 31,

2023

2022
Foreign currency translation$1,437 $1,435 
Derivative instruments designated as cash flow hedges(7,223)(7,675)
Postretirement medical plans273 534 
Accumulated other comprehensive loss$(5,513)$(5,706)

The following table displays the changes in AOCI by component, net of tax (in thousands):

December 31,2023
Year Ended
Affected Line Item in the Statements of Income
Interest Rate Derivative Instruments Designated as
Cash Flow
Hedges
Postretirement Medical PlansForeign Currency Translation

Total
Beginning balance$(7,675)$534 $1,435 $(5,706)
Other comprehensive income before reclassifications
Amounts reclassified from AOCI
Interest on
long-term debt
452 452 
Amounts reclassified from AOCI(261)(261)
Net current-period other comprehensive income452 (261)193 
Ending Balance$(7,223)$273 $1,437 $(5,513)

December 31,2022
Year Ended
Affected Line Item in the Statements of Income
Interest
Rate
Derivative Instruments Designated
as Cash
Flow Hedges
Postretirement Medical PlansForeign Currency Translation

Total
Beginning balance$(8,127)$1,516 $1,443 $(5,168)
Other comprehensive income before reclassifications(8)(8)
Amounts reclassified from AOCI
Interest on
long-term debt
452 452 
Amounts reclassified from AOCI(982)(982)
Net current-period other comprehensive income452 (982)(8)(538)
Ending Balance$(7,675)$534 $1,435 $(5,706)
(16)Employee Benefit Plans

Pension and Other Postretirement Benefit Plans

We sponsor and/or contribute to pension and postretirement health care and life insurance benefit plans for eligible employees. The pension plan for our South Dakota and Nebraska employees is referred to as the NorthWestern Corporation plan, the pension plan for our Montana employees is referred to as the NorthWestern Energy plan, and collectively they are referred to as the Plans. We utilize a number of accounting mechanisms that reduce the volatility of reported pension costs. Differences between actuarial assumptions and actual plan results are deferred and are recognized into earnings only when the accumulated differences exceed 10 percent of the greater of the projected benefit obligation or the market-related value of plan assets. If necessary, the excess is amortized over the average remaining service period of active employees. The Plans' funded status is recognized as an asset or liability in our Financial Statements. See Note 5 - Regulatory Assets and Liabilities, for further discussion on how these costs are recovered through rates charged to our customers.

Benefit Obligation and Funded Status

Following is a reconciliation of the changes in plan benefit obligations and fair value of plan assets, and a statement of the funded status (in thousands):
Pension BenefitsOther Postretirement Benefits
December 31,December 31,

2023

20222023

2022
Change in benefit obligation:
Obligation at beginning of period$521,798 $696,802 $15,407 $17,308 
Service cost5,646 10,223 333 351 
Interest cost25,852 18,787 674 358 
Actuarial loss3,127 (176,389)(1,240)(99)
Settlements(1)
(51,942)— — — 
Benefits paid(30,493)(27,625)(1,466)(2,511)
Benefit Obligation at End of Period$473,988 $521,798 $13,708 $15,407 
Change in Fair Value of Plan Assets:
Fair value of plan assets at beginning of period$441,539 $605,499 $20,055 $25,289 
Return on plan assets34,367 (144,535)3,334 (4,098)
Employer contributions9,200 8,200 386 1,375 
Settlements(1)
(51,942)— — — 
Benefits paid(30,493)(27,625)(1,466)(2,511)
Fair value of plan assets at end of period$402,671 $441,539 $22,309 $20,055 
Funded Status$(71,317)$(80,259)$8,601 $4,648 
Amounts Recognized in the Balance Sheet Consist of:
Noncurrent asset7,875 7,195 12,378 8,831 
Total Assets7,875 7,195 12,378 8,831 
Current liability(11,200)(11,200)(1,355)(1,585)
Noncurrent liability(67,992)(76,254)(2,422)(2,598)
Total Liabilities(79,192)(87,454)(3,777)(4,183)
Net amount recognized$(71,317)$(80,259)$8,601 $4,648 
Amounts Recognized in Regulatory Assets Consist of:
Prior service credit— — — (116)
Net actuarial loss(44,453)(54,383)15 (3,123)
Amounts recognized in AOCI consist of:
Prior service cost— — — — 
Net actuarial gain— — 590 1,046 
Total$(44,453)$(54,383)$605 $(2,193)
(1) In October 2023, we entered into a group annuity contract from an insurance company to provide for the payment of pension benefits to 285 NorthWestern Energy Pension Plan participants. We purchased the contract with $51.9 million of plan assets. The insurance company took over the payments of these benefits starting January 1, 2024. This transaction settled $51.9 million of our NorthWestern Energy Pension Plan obligation. As a result of this transaction, during the twelve months ended December 31, 2023, we recorded a non-cash, non-operating settlement charge of $4.4 million. This charge is recorded within operating expense, net on the Statements of Income. As discussed within Note 5 – Regulatory Assets and Liabilities, the MPSC allows recovery of pension costs on a cash funding basis. As such, this charge was deferred as a regulatory asset on the Balance Sheets, with a corresponding decrease to operating expense on the Statements of Income.

The actuarial gain/loss is primarily due to the change in discount rate assumption and actual asset returns compared with expected amounts. The total projected benefit obligation and fair value of plan assets for the pension plans with accumulated benefit obligations in excess of plan assets were as follows (in millions):
NorthWestern Energy Pension Plan
December 31,

2023

2022
Projected benefit obligation$427.3 $474.9 
Accumulated benefit obligation427.3 474.9 
Fair value of plan assets348.1 388.7 
_____________________
As of December 31, 2023, the fair value of the NorthWestern Corporation pension plan assets exceed the total projected and accumulated benefit obligation and are therefore excluded from this table.

Net Periodic Cost (Credit)

The components of the net costs (credits) for our pension and other postretirement plans are as follows (in thousands):

Pension Benefits
Other Postretirement
Benefits
December 31,December 31,

2023

20222023

2022
Components of Net Periodic Benefit Cost
Service cost$5,646 $10,223 $333 $351 
Interest cost25,852 18,787 674 359 
Expected return on plan assets(25,932)(24,173)(1,096)(1,047)
Amortization of prior service cost (credit)— — 116 (1,891)
Recognized actuarial loss (gain)228 383 (672)(897)
Settlement loss recognized(1)
4,395 — — — 
Net Periodic Benefit Cost (Credit)$10,189 $5,220 $(645)$(3,125)
Regulatory deferral of net periodic benefit cost(2)
(1,814)2,307 — — 
Previously deferred costs recognized(2)
210 — 550 292 
Amount Recognized in Income$8,585 $7,527 $(95)$(2,833)
_________________________
(1) Settlement losses are related to partial annuitization of NorthWestern Energy Pension Plan effective October 24, 2023 and December 1, 2021, respectively.
(2) Net periodic benefit costs for pension and postretirement benefit plans are recognized for financial reporting based on the authorization of each regulatory jurisdiction in which we operate. A portion of these costs are recorded in regulatory assets and recognized in the Statements of Income as those costs are recovered through customer rates.

For the years ended December 31, 2023 and 2022, Service costs were recorded in Operations and maintenance expense while non-service costs were recorded in Other income, net on the Statements of Income.

For purposes of calculating the expected return on pension plan assets, the market-related value of assets is used, which is based upon fair value. The difference between actual plan asset returns and estimated plan asset returns are amortized equally over a period not to exceed five years.

Actuarial Assumptions
The measurement dates used to determine pension and other postretirement benefit measurements for the plans are December 31, 2023 and 2022. The actuarial assumptions used to compute net periodic pension cost and postretirement benefit cost are based upon information available as of the beginning of the year, specifically, market interest rates, past experience and management's best estimate of future economic conditions. Changes in these assumptions may impact future benefit costs and obligations. In computing future costs and obligations, we must make assumptions about such things as employee mortality and turnover, expected salary and wage increases, discount rate, expected return on plan assets, and expected future cost increases. Two of these assumptions have the most impact on the level of cost: (1) discount rate and (2) expected rate of return on plan assets. During 2022, the plan's actuary conducted an experience study to review five years of plan experience and update these assumptions.

On an annual basis, we set the discount rate using a yield curve analysis. This analysis includes constructing a hypothetical bond portfolio whose cash flow from coupons and maturities matches the year-by-year, projected benefit cash flow from our plans. The decrease in the discount rate during 2023 increased our projected benefit obligation by approximately $10.5 million.

In determining the expected long-term rate of return on plan assets, we review historical returns, the future expectations for returns for each asset class weighted by the target asset allocation of the pension and postretirement portfolios, and long-term inflation assumptions. Based on the target asset allocation for our pension assets and future expectations for asset returns, we increased our long term rate of return on assets assumption for NorthWestern Energy Pension Plan to 6.65 percent and increased our assumption on the NorthWestern Corporation Pension Plan to 5.15 percent for 2024.

The weighted-average assumptions used in calculating the preceding information are as follows:

Pension Benefits
Other Postretirement
Benefits
December 31,December 31,

2023

20222023

2022
Discount rate4.95-5.00%5.20%4.85-4.90%5.15-5.20%
Expected rate of return on assets4.83-6.442.66-4.265.62 4.23 
Long-term rate of increase in compensation levels (non-union)
4.00 4.00 4.00 4.00 
Long-term rate of increase in compensation levels (union)4.00 4.00 4.00 4.00 
Interest crediting rate3.30-6.003.30-6.00N/AN/A

The postretirement benefit obligation is calculated assuming that health care costs increase by a 5.00 percent fixed rate. The company contribution toward the premium cost is capped, therefore future health care cost trend rates are expected to have a minimal impact on company costs and the accumulated postretirement benefit obligation.

Investment Strategy

Our investment goals with respect to managing the pension and other postretirement assets are to meet current and future benefit payment needs while maximizing total investment returns (income and appreciation) after inflation within the constraints of diversification, prudent risk taking, Prudent Man Rule of the Employee Retirement Income Security Act of 1974 and liability-based considerations. Each plan is diversified across asset classes to achieve optimal balance between risk and return and between income and growth through capital appreciation. Our investment philosophy is based on the following:

Each plan should be substantially invested as long-term cash holdings reduce long-term rates of return;
Pension Plan portfolio risk is described by volatility in the funded status of the Plans;
It is prudent to diversify each plan across the major asset classes;
Equity investments provide greater long-term returns than fixed income investments, although with greater short-term volatility;
Fixed income investments of the plans should strongly correlate with the interest rate sensitivity of the plan’s aggregate liabilities in order to hedge the risk of change in interest rates negatively impacting the pension plans overall funded status, (such assets will be described as Liability Hedging Fixed Income assets);
Allocation to foreign equities increases the portfolio diversification and thereby decreases portfolio risk while providing for the potential for enhanced long-term returns;
Private real estate and broad global opportunistic fixed income asset classes can provide diversification to both equity and liability hedging fixed income investments and that a moderate allocation to each can potentially improve the expected risk-adjusted return for the NorthWestern Energy Pension Plan investments over full market cycles;
Active management can reduce portfolio risk and potentially add value through security selection strategies;
A portion of plan assets should be allocated to passive, indexed management funds to provide for greater diversification and lower cost; and
It is appropriate to retain more than one investment manager, provided that such managers offer asset class or style diversification.

Investment risk is measured and monitored on an ongoing basis through quarterly investment portfolio reviews, annual liability measurements, and periodic asset/liability studies.

The most important component of an investment strategy is the portfolio asset mix, or the allocation between the various classes of securities available. The mix of assets is based on an optimization study that identifies asset allocation targets in order to achieve the maximum return for an acceptable level of risk, while minimizing the expected contributions and pension and postretirement expense. In the optimization study, assumptions are formulated about characteristics, such as expected asset class investment returns, volatility (risk), and correlation coefficients among the various asset classes, and making adjustments to reflect future conditions expected to prevail over the study period. Based on this, the target asset allocation established, within an allowable range of plus or minus 5 percent, is as follows:

NorthWestern Energy
Pension
NorthWestern
Corporation Pension
NorthWestern Energy
Health and Welfare
December 31,December 31,December 31,

2023

20222023

20222023

2022
Fixed income securities45.0 %45.0 %90.0 %90.0 %40.0 %40.0 %
Non-U.S. fixed income securities— — — 1.0 — — 
Opportunistic fixed income11.0 5.5 3.0 — — — 
Global equities38.5 44.0 7.0 9.0 60.0 60.0 
Private real estate5.5 5.5 — — — — 

The actual allocation by plan is as follows:
NorthWestern Energy
Pension
NorthWestern
Corporation Pension
NorthWestern Energy
Health and Welfare
December 31,December 31,December 31,

2023

20222023

20222023

2022
Cash and cash equivalents— %— %1.5 %1.1 %0.2 %0.6 %
Fixed income securities45.3 44.5 88.7 88.6 35.1 36.7 
Non-U.S. fixed income securities— — — 0.9 — — 
Opportunistic fixed income10.6 5.5 2.9 — — — 
Global equities37.6 43.4 6.9 9.4 64.7 62.7 
Private real estate6.5 %6.6 %— %— %— %— %
100.0 %100.0 %100.0 %100.0 %100.0 %100.0 %

Generally, the asset mix will be rebalanced to the target mix as individual portfolios approach their minimum or maximum levels. The guidelines allow for a transition to targets over time as assets are reallocated to newly-approved asset classes of opportunistic fixed income and private real estate. Debt securities consist of U.S. and international instruments including emerging markets and high yield instruments, as well as government, corporate, asset backed and mortgage backed securities. While the portfolio may invest in high yield securities, the average quality must be rated at least “investment grade" by rating agencies. Equity, real estate and fixed income portfolios may be comprised of both active and passive management strategies. Performance of fixed income investments is measured by both traditional investment benchmarks as well as relative changes in the present value of the plan's liabilities. Equity investments consist primarily of U.S. stocks including large, mid and small cap stocks. We also invest in global equities with exposure to developing and emerging markets. Equity investments may also be diversified across investment styles such as growth and value. Derivatives, options and futures are permitted for the purpose of reducing risk but may not be used for speculative purposes. Real estate investments will consist of global equity or debt interests in tangible property consisting of land, buildings, and other improvements in commercial and residential sectors.

Our plan assets are primarily invested in common collective trusts (CCTs), which are invested in equity and fixed income securities. In accordance with our investment policy, these pooled investment funds must have an adequate asset base relative to their asset class and be invested in a diversified manner and have a minimum of three years of verified investment performance experience or verified portfolio manager investment experience in a particular investment strategy and have management and oversight by an investment advisor registered with the Securities and Exchange Commission (SEC). Investments in a collective investment vehicle are valued by multiplying the investee company’s net asset value per share with the number of units or shares owned at the valuation date. Net asset value per share is determined by the trustee. Investments held by the CCT, including collateral invested for securities on loan, are valued on the basis of valuations furnished by a pricing service approved by the CCT’s investment manager, which determines valuations using methods based on quoted closing market prices on national securities exchanges, or at fair value as determined in good faith by the CCT’s investment manager if applicable. The funds do not contain any redemption restrictions. The direct holding of NorthWestern Energy Group stock is not permitted; however, any holding in a diversified mutual fund or collective investment fund is permitted.

Cash Flows

In accordance with the Pension Protection Act of 2006 (PPA), and the relief provisions of the Worker, Retiree, and Employer Recovery Act of 2008 (WRERA), we are required to meet minimum funding levels in order to avoid required contributions and benefit restrictions. We have elected to use asset smoothing provided by the WRERA, which allows the use of asset averaging, including expected returns (subject to certain limitations), for a 24-month period in the determination of funding requirements. Additional funding relief was passed in the American Rescue Plan Act of 2021, providing for longer amortization and interest rate smoothing, which we elected to use. We expect to continue to make contributions to the pension plans in 2024 and future years that reflect the minimum requirements and discretionary amounts consistent with the amounts recovered in rates. Additional legislative or regulatory measures, as well as fluctuations in financial market conditions, may impact our funding requirements.
Due to the regulatory treatment of pension costs in Montana, pension costs for 2023 and 2022 were based on actual contributions to the plan. Annual contributions to each of the pension plans are as follows (in thousands):


2023

2022
NorthWestern Energy Pension Plan (MT)$8,000 $7,000 
NorthWestern Corporation Pension Plan (SD and NE)1,200 1,200 
$9,200 $8,200 

We estimate the plans will make future benefit payments to participants as follows (in thousands):


Pension Benefits

Other Postretirement Benefits
2024$27,553 $2,149 
202528,987 1,813 
202629,920 1,406 
202730,545 1,251 
202831,231 1,210 
2029-2032164,362 5,288 

Defined Contribution Plan

Our defined contribution plan permits employees to defer receipt of compensation as provided in Section 401(k) of the Internal Revenue Code. Under the plan, employees may elect to direct a percentage of their gross compensation to be contributed to the plan. We contribute various percentage amounts of the employee's gross compensation contributed to the plan. Matching contributions for the years ended December 31, 2023 and 2022 were $13.2 million and $12.3 million, respectively.
(17)Stock-Based Compensation

We grant stock-based awards through our Amended and Restated Equity Compensation Plan (ECP), which includes restricted stock awards and performance share awards. These stock-based awards are for the common stock of NorthWestern Energy Group, Inc. As part of effectuating the holding company reorganization, all outstanding and unexercised, unvested and not yet paid or payable stock-based awards were converted into a right to acquire NorthWestern Energy Group, Inc. capital stock of the same class and with the same rights and privileges relative to the stock-based award prior to the merger. See Note 1 - Nature of Operations for further information regarding the holding company effectuation in 2023.

As of December 31, 2023, there were 649,884 shares of common stock remaining available for grants. The remaining vesting period for awards previously granted ranges from one to four years if the service and/or performance requirements are met. Nonvested shares do not receive dividend distributions. The long-term incentive plan provides for accelerated vesting in the event of a change in control.

We account for our share-based compensation arrangements by recognizing compensation costs for all share-based awards over the respective service period for employee services received in exchange for an award of equity or equity-based compensation. The compensation cost is based on the fair value of the grant on the date it was awarded.
Performance Unit Awards

Performance unit awards are granted annually under the ECP. These awards vest at the end of the three-year performance period if we have achieved certain performance goals and the individual remains employed by us. The exact number of shares issued will vary from 0 percent to 200 percent of the target award, depending on actual company performance relative to the performance goals. Beginning in 2023, these awards contain service-, market-, and performance-based components. The service-based component of these awards, representing 30 percent of the award, vest at the end of the three-year performance period as long as the individual has remained employed with us over that term. The performance goals are independent of each other and equally weighted at 35 percent of the award, and are based on two metrics: (i) EPS growth level and average return on equity; and (ii) total shareholder return relative to a peer group. Performance unit awards issued prior to 2023 included both the market- and performance-based components discussed above.

Fair value is determined for each component of the performance unit awards. The fair value of the service-based component is estimated based upon the closing market price of our common stock as of the grant date less the present value of expected dividends. The fair value of the performance-based component is estimated based upon the closing market price of our common stock as of the grant date less the present value of expected dividends, multiplied by an estimated performance multiple determined on the basis of historical experience, which is subsequently trued up at vesting based on actual performance. The fair value of the market-based component is estimated using a statistical model that incorporates the probability of meeting performance targets based on historical returns relative to the peer group. The following summarizes the significant assumptions used to determine the fair value of performance shares and related compensation expense as well as the resulting estimated fair value of performance shares granted:

2023

2022
Risk-free interest rate4.33 %1.82 %
Expected life, in years33
Expected volatility30.4% to 41.0%28.2% to 38.8%
Dividend yield4.4 %4.5 %

The risk-free interest rate was based on the U.S. Treasury yield of a three-year bond at the time of grant. The expected term of the performance shares is three years based on the performance cycle. Expected volatility was based on the historical volatility for the peer group. Both performance goals are measured over the three-year vesting period and are charged to compensation expense over the vesting period based on the number of shares expected to vest.

A summary of nonvested shares as of and changes during the year ended December 31, 2023, are as follows:

Performance Unit Awards

Shares

Weighted-Average Grant-Date
Fair Value
Beginning nonvested grants194,407 $51.04 
Granted95,853 54.41 
Vested(87,300)50.53 
Forfeited(49,176)51.59 
Remaining nonvested grants153,784 $53.26 

Retirement/Retention Restricted Share Awards

In December 2011, an executive retirement / retention program was established that provides for the annual grant of restricted share units. Awards granted before 2022 are subject to a five-year performance and vesting period. The performance measure for these awards requires net income for the calendar year of at least three of the five full calendar
years during the performance period to exceed net income for the calendar year the awards are granted. Awards granted in 2022 no longer contain this performance measure, instead these awards will vest after five full calendar years if the employee remains employed during that service period. No retirement/retention restricted shares were granted during the year ended December 31, 2023. Once vested, the awards will be paid out in shares of common stock in five equal annual installments after a recipient has separated from service. The fair value of these awards is measured based upon the closing market price of our common stock as of the grant date less the present value of expected dividends.


A summary of nonvested shares as of and changes during the year ended December 31, 2023, are as follows:


Shares

Weighted-Average Grant-Date
Fair Value
Beginning nonvested grants99,285 $48.62 
Granted— — 
Vested— — 
Forfeited(38,506)49.73 
Remaining nonvested grants60,779 $47.91 

We recognized total stock-based compensation expense of $3.6 million and $4.2 million for the years ended December 31, 2023 and 2022, respectively, and related income tax benefit of $(1.0) million and $(1.3) million for the years ended December 31, 2023 and 2022, respectively. As of December 31, 2023, we had $6.5 million of unrecognized compensation cost related to the nonvested portion of our outstanding awards. The cost is expected to be recognized over a weighted-average period of 2 years. The total fair value of shares vested was $4.4 million and $4.3 million for the years ended December 31, 2023 and 2022, respectively.
(18)Common Stock

We have 250,000,000 shares authorized consisting of 200,000,000 shares of common stock with a $0.01 par value and 50,000,000 shares of preferred stock with a $0.01 par value.

Repurchase of Common Stock

Shares tendered by employees to us to satisfy the employees' tax withholding obligations in connection with the vesting of restricted stock awards totaled 4,167 and 16,120 during the years ended December 31, 2023 and 2022, respectively, and are reflected in reacquired capital. These shares were credited to reacquired capital based on their fair market value on the vesting date.

Issuance of Common Stock

In April 2021, NorthWestern Corporation entered into an Equity Distribution Agreement pursuant to which we could offer and sell shares of our common stock from time to time, having an aggregate gross sales price of up to $200.0 million, through an At-the-Market (ATM) offering program. During the twelve months ended December 31, 2023, NorthWestern Corporation issued 1,432,738 shares of our common stock under the ATM program at an average price of $52.02, for net proceeds of $73.6 million, which is net of sales commissions and other fees paid of approximately $0.9 million. We have completed the ATM offering program under this Equity Distribution Agreement.
(19)Commitments and Contingencies
Qualifying Facilities Liability

Our QF liability primarily consists of unrecoverable costs associated with three contracts covered under the Public Utility Regulatory Practices Act (PURPA). These contracts require us to purchase minimum amounts of energy at prices ranging from $67 to $136 per MWH through 2029. As of December 31, 2023, our estimated gross contractual obligation related to these contracts was approximately $303.1 million through 2029. A portion of the costs incurred to purchase this energy is recoverable through rates, totaling approximately $266.5 million through 2029. As contractual obligations are settled, the related purchases and sales are recorded within operating expense and operating revenues in our Statements of Income. The present value of the remaining liability is recorded in Accumulated miscellaneous operating provisions in our Balance Sheets. The following summarizes the change in the liability (in thousands):

December 31,

2023

2022
Beginning QF liability$49,728 $64,943 
Settlements(1)
(24,707)(20,076)
Interest on long-term debt3,649 4,861 
Ending QF liability$28,670 $49,728 
______________________
(1) The primary components of the change in settlement amounts includes (i) a lower periodic adjustment of $4.2 million due to actual price escalation, which was less than previously modeled; and (ii) higher costs of approximately $1.0 million, due to a $0.8 million reduction in costs for the adjustment to actual output and pricing for the current contract year as compared with a $1.8 million reduction in costs in the prior period.

The following summarizes the estimated gross contractual obligation less amounts recoverable through rates (in thousands):


Gross
Obligation

Recoverable
Amounts
Net
2023$74,110 $60,706 $13,404 
202460,360 52,950 7,410 
202555,393 46,274 9,119 
202656,665 46,668 9,997 
202742,400 41,664 736 
Thereafter14,134 18,231 (4,097)
Total(1)
$303,062 $266,493 $36,569 
_____________________
(1) This net unrecoverable amount represents the undiscounted difference between the total gross obligations and recoverable amounts. The ending QF liability in the table above represents the present value of this net unrecoverable amount.

Long Term Supply and Capacity Purchase Obligations

We have entered into various commitments, largely purchased power, electric transmission, coal and natural gas supply and natural gas transportation contracts. These commitments range from one to 24 years. Costs incurred under these contracts are included in Operating expense in the Statements of Income and were approximately $340.0 million and $328.0 million for the years ended December 31, 2023 and 2022, respectively. As of December 31, 2023, our commitments under these contracts were $321.9 million in 2024, $244.1 million in 2025, $263.4 million in 2026, $243.6 million in 2027, $225.9 million in 2028, and $1.5 billion thereafter. These commitments are not reflected in our Financial Statements.

Hydroelectric License Commitments
With the 2014 purchase of hydroelectric generating facilities and associated assets located in Montana, we assumed two Memoranda of Understanding (MOUs) existing with state, federal and private entities. The MOUs are periodically updated and renewed and require us to implement plans to mitigate the impact of the projects on fish, wildlife and their habitats, and to increase recreational opportunities. The MOUs were created to maximize collaboration between the parties and enhance the possibility to receive matching funds from relevant federal agencies. Under these MOUs, we have a remaining commitment to spend approximately $22.4 million between 2024 and 2040. These commitments are not reflected in our Financial Statements.

ENVIRONMENTAL LIABILITIES AND REGULATION

Environmental Matters

The operation of electric generating, transmission and distribution facilities, and gas gathering, storage, transportation and distribution facilities, along with the development (involving site selection, environmental assessments, and permitting) and construction of these assets, are subject to extensive federal, state, and local environmental and land use laws and regulations. Our activities involve compliance with diverse laws and regulations that address emissions and impacts to the environment, including air and water, protection of natural resources, avian and wildlife. We monitor federal, state, and local environmental initiatives to determine potential impacts on our financial results. As new laws or regulations are implemented, our policy is to assess their applicability and implement the necessary modifications to our facilities or their operation to maintain ongoing compliance.

Our environmental exposure includes a number of components, including remediation expenses related to the cleanup of current or former properties, and costs to comply with changing environmental regulations related to our operations. At present, our environmental reserve, which relates primarily to the remediation of former manufactured gas plant sites owned by us or for which we are responsible, is estimated to range between $21.0 million to $31.4 million. As of December 31, 2023, we had a reserve of approximately $25.3 million, which has not been discounted. Environmental costs are recorded when it is probable we are liable for the remediation and we can reasonably estimate the liability. We use a combination of site investigations and monitoring to formulate an estimate of environmental remediation costs for specific sites. Our monitoring procedures and development of actual remediation plans depend not only on site specific information but also on coordination with the different environmental regulatory agencies in our respective jurisdictions; therefore, while remediation exposure exists, it may be many years before costs are incurred.

The following summarizes the change in our environmental liability (in thousands):
December 31,

2023

2022
Liability at January 1,$26,367 $26,866 
Deductions(2,520)(2,033)
Charged to costs and expense1,439 1,534 
Liability at December 31,$25,285 $26,367 


Over time, as costs become determinable, we may seek authorization to recover such costs in rates or seek insurance reimbursement as available and applicable; therefore, although we cannot guarantee regulatory recovery, we do not expect these costs to have a material effect on our financial position or results of operations.

Manufactured Gas Plants - Approximately $19.8 million of our environmental reserve accrual is related to the following manufactured gas plants.

South Dakota - A formerly operated manufactured gas plant located in Aberdeen, South Dakota, has been identified on the Federal Comprehensive Environmental Response, Compensation, and Liability Information System list as contaminated
with coal tar residue. We are currently conducting feasibility studies, implementing remedial actions pursuant to work plans approved by the South Dakota Department of Agriculture and Natural Resources, and conducting ongoing monitoring and operation and maintenance activities. As of December 31, 2023, the reserve for remediation costs at this site was approximately $8.0 million, and we estimate that approximately $2.9 million of this amount will be incurred through 2028.

Nebraska - We own sites in North Platte, Kearney, and Grand Island, Nebraska on which former manufactured gas facilities were located. We are currently working independently to fully characterize the nature and extent of potential impacts associated with these Nebraska sites. Our reserve estimate includes assumptions for site assessment and remedial action work. At present, we cannot determine with a reasonable degree of certainty the nature and timing of any risk-based remedial action at our Nebraska locations.

Montana - We own or have responsibility for sites in Butte, Missoula, and Helena, Montana on which former manufactured gas plants were located. The Butte and Helena sites, both listed as high priority sites on Montana’s state superfund list, were placed into the MDEQ voluntary remediation program for cleanup due to soil and groundwater impacts. Soil and coal tar were removed at the sites in accordance with the MDEQ requirements. Groundwater monitoring is conducted semiannually at both sites. At this time, we cannot estimate with a reasonable degree of certainty the nature and timing of additional remedial actions and/or investigations, if any, at the Butte site.

In August 2016, the MDEQ sent us a Notice of Potential Liability and Request for Remedial Action regarding the Helena site. In October 2019, we submitted a third revised Remedial Investigation Work Plan (RIWP) for the Helena site addressing MDEQ comments. The MDEQ approved the RIWP in March 2020 and field work was completed in 2022. We submitted a Remedial Investigation Report (RI Report) summarizing the work completed to MDEQ in March 2022 and are awaiting its review and comments as to any additional field work. We now expect the MDEQ review of the RI Report to be concluded in 2024, and any additional field work to commence following that.

MDEQ has indicated it expects to proceed in listing the Missoula site as a Montana superfund site. After researching historical ownership, we have identified another potentially responsible party with whom we have entered into an agreement allocating third-party costs to be incurred in addressing the site. The other party has assumed the lead role at the site and has expressed its intention to submit a voluntary remediation plan for the Missoula site to MDEQ. At this time, we cannot estimate with a reasonable degree of certainty the nature and timing of risk-based remedial action, if any, at the Missoula site.

Global Climate Change - National and international actions have been initiated to address global climate change and the contribution of GHG including, most significantly, carbon dioxide (CO2) and methane emissions from natural gas. These actions include legislative proposals, Executive, Congressional and EPA actions at the federal level, state level activity, investor activism and private party litigation relating to emissions. Coal-fired plants have come under particular scrutiny due to their level of emissions. We have joint ownership interests in four coal-fired electric generating plants, all of which are operated by other companies. We are responsible for our proportionate share of the capital and operating costs while being entitled to our proportionate share of the power generated.

Proposed EPA Rules - Congress has not passed any federal climate change legislation regarding GHG emissions from coal fired plants, and we cannot predict the timing or form of any potential legislation. Section 111(d) of the Clean Air Act (CAA) confers authority on EPA and the states to regulate emissions, including GHGs, from existing stationary sources. In May 2023, EPA proposed new GHG emissions standards for coal and natural gas-fired plants. In particular, the proposed rules would (i) strengthen the current New Source Performance Standards for newly built fossil fuel-fired stationary combustion turbines (generally natural gas-fired); (ii) establish emission guidelines for states to follow in limiting carbon pollution from existing fossil fuel-fired steam generating electric generating units (including coal, oil and natural gas-fired units); and (iii) establish emission guidelines for large, frequently used existing fossil fuel-fired stationary combustion turbines (generally natural gas-fired). In addition, in April 2023, EPA proposed to amend the MATS. Among other things, MATS currently sets stringent emission limits for acid gases, mercury, and other hazardous air pollutants from new and existing electric generating units. We are in compliance with existing MATS requirements. The proposed amendment of the MATS would strengthen the MATS requirements, and if adopted as written, both the GHG and MATS proposed rules could have a material negative impact on our coal-fired plants, including requiring potentially expensive upgrades or the early retirement of Colstrip Unit's 3 and 4 due to the rules making the facility uneconomic.
Previous efforts by the EPA were met with extensive litigation and we anticipate a similar response if the proposed rules are adopted. As MATS and GHG regulations are implemented, it could result in additional material compliance costs. We will continue working with federal and state regulatory authorities, other utilities, and stakeholders to seek relief from any MATS or GHG regulations that, in our view, disproportionately impact customers in our region.

Future additional environmental requirements - federal or state - could cause us to incur material costs of compliance, increase our costs of procuring electricity, decrease transmission revenue and impact cost recovery. Technology to efficiently capture, remove and/or sequester such GHG emissions or hazardous air pollutants may not be available within a timeframe consistent with the implementation of any such requirements.

Regional Haze Rules - In January 2017, the EPA published amendments to the requirements under the CAA for state plans for protection of visibility - regional haze rules. Among other things, these amendments revised the process and requirements for the state implementation plans and extended the due date for the next periodic comprehensive regional haze state implementation plan revisions from 2018 to 2021.

The states of Montana, North Dakota and South Dakota have developed and submitted to the EPA, for its approval, their respective State Implementation Plans (SIP) for Regional Haze compliance. While these states, among others, did not meet the EPA’s July 31, 2021 submission deadline, they were all submitted in 2022. The Montana SIP as drafted and submitted to EPA does not call for additional controls for our interest in Colstrip Unit 4. The draft North Dakota SIP does not require any additional controls at the Coyote generating facility. Similarly, the draft South Dakota SIP does not require any additional controls at the Big Stone generating facility. Until these SIPs are finalized and approved by EPA, the potential remains that installation of additional emissions controls might be required at these facilities.

Jointly Owned Plants - We have joint ownership in generation plants located in South Dakota, North Dakota, Iowa, and Montana that are or may become subject to the various regulations discussed above that have been or may be issued or proposed.

Other - We continue to manage equipment containing polychlorinated biphenyl (PCB) oil in accordance with the EPA's Toxic Substance Control Act regulations. We will continue to use certain PCB-contaminated equipment for its remaining useful life and will, thereafter, dispose of the equipment according to pertinent regulations that govern the use and disposal of such equipment.

We routinely engage the services of a third-party environmental consulting firm to assist in performing a comprehensive evaluation of our environmental reserve. Based upon information available at this time, we believe that the current environmental reserve properly reflects our remediation exposure for the sites currently and previously owned by us. The portion of our environmental reserve applicable to site remediation may be subject to change as a result of the following uncertainties:

We may not know all sites for which we are alleged or will be found to be responsible for remediation; and
Absent performance of certain testing at sites where we have been identified as responsible for remediation, we cannot estimate with a reasonable degree of certainty the total costs of remediation.

LEGAL PROCEEDINGS

State of Montana - Riverbed Rents

On April 1, 2016, the State of Montana (State) filed a complaint on remand (the State’s Complaint) with the Montana First Judicial District Court (State District Court), naming us, along with Talen Montana, LLC (Talen) as defendants. The State claimed it owns the riverbeds underlying 10 of our, and formerly Talen’s, hydroelectric facilities (dams, along with reservoirs and tailraces) on the Missouri, Madison and Clark Fork Rivers, and seeks rents for Talen’s and our use and occupancy of such lands. The facilities at issue include the Hebgen, Madison, Hauser, Holter, Black Eagle, Rainbow, Cochrane, Ryan, and Morony facilities on the Missouri and Madison Rivers and the Thompson Falls facility on the Clark Fork River. We acquired these facilities from Talen in November 2014.
The litigation has a long prior history. In 2012, the United States Supreme Court issued a decision holding that the Montana Supreme Court erred in not considering a segment-by-segment approach to determine navigability and relying on present day recreational use of the rivers. It also held that what it referred to as the Great Falls Reach “at least from the head of the first waterfall to the foot of the last” was not navigable for title purposes, and thus the State did not own the riverbeds in that segment. The United States Supreme Court remanded the case to the Montana Supreme Court for further proceedings not inconsistent with its opinion. Following the 2012 remand, the case laid dormant for four years until the State’s Complaint was filed with the State District Court. On April 20, 2016, we removed the case from State District Court to the United States District Court for the District of Montana (Federal District Court). On August 1, 2018, the Federal District Court granted our and Talen’s motions to dismiss the State’s Complaint as it pertains to the navigability of the riverbeds associated with four of our hydroelectric facilities near Great Falls. A bench trial before the Federal District Court commenced January 4, 2022, and concluded on January 18, 2022, which addressed the issue of navigability concerning our other six facilities. On August 25, 2023, the Federal District Court issued its Findings of Fact, Conclusions of Law and Order (the "Order"), which found all but one of the segments of the riverbeds in dispute not navigable, and thus not owned by the State of Montana. The one segment found navigable, and thus owned by the State, was the segment on which the Black Eagle development was located. The State filed a motion to pursue an interlocutory appeal of the Order, and on January 2, 2024, the Federal District Court certified the Order for appeal to the 9th Circuit Court of Appeals. Damages were bifurcated by agreement and will be tried separately for the Black Eagle segment, and any other segments found navigable should an appeal be granted and other segments found navigable.

We dispute the State’s claims and intend to continue to vigorously defend the lawsuit. If the Federal District Court calculates damages as the State District Court did in 2008, we do not anticipate the resulting annual rent for the Black Eagle segment would have a material impact to our financial position or results of operations. We anticipate that any obligation to pay the State rent for use and occupancy of the riverbeds would be recoverable in rates from customers, although there can be no assurances that the MPSC would approve any such recovery.

Colstrip Arbitration

The remaining depreciable life of our investment in Colstrip Unit 4 is through 2042. The six owners of Colstrip Units 3 and 4 currently share the operating costs pursuant to the terms of an Ownership and Operation Agreement (O&O Agreement). However, several of the owners are mandated by Washington and Oregon law to eliminate coal-fired resources in 2025 and 2029, respectively.

As a result of the mandate, the owners have disagreed on various operational funding decisions, including whether closure requires each owner’s consent under the O&O Agreement. On March 12, 2021, we initiated an arbitration under the O&O Agreement (the “Arbitration”), to resolve the issues of whether closure requires each owner's consent and to clarify each owner's obligations to continue to fund operations until all joint owners agree on closure. The owners previously initiated efforts to identify arbitrators and have agreed to stay the Arbitration through March 31, 2024, while they explore a potential resolution to their disagreements.

Colstrip Coal Dust Litigation

On December 14, 2020, a claim was filed against Talen in the Montana Sixteenth Judicial District Court, Rosebud County, Cause No. CV-20-58. Talen is one of the co-owners of Colstrip Unit 3, and the operator of Units 3 and 4. The plaintiffs allege they have suffered adverse effects from coal dust generated during operations associated with Colstrip. On August 26, 2021, the claim was amended to add in excess of 100 plaintiffs. It also added NorthWestern, the other owners of Colstrip, and Westmoreland Rosebud Mining LLC, as defendants. Plaintiffs are seeking economic damages, costs and disbursements, punitive damages, attorneys’ fees, and an injunction prohibiting defendants from allowing coal dust to blow onto plaintiffs’ properties.

Since this lawsuit remains in its discovery stages, we are unable to predict outcomes. We continue to evaluate a range of reasonably possible losses.

BNSF Demands for Indemnity and Remediation Costs
NorthWestern has received a demand for indemnity from BNSF Railway Company (BNSF) for past and future environmental investigation and remediation costs incurred by BNSF at one of the three operable units at the Anaconda Copper Mining (ACM) Smelter and Refinery Superfund Site, located near Great Falls, Montana. Smelter and refining operations at the site commenced in 1893 and continued until 1980.

NorthWestern owns property in the Railroad Corridor sub-section of Operable Unit 1. BNSF claims it is entitled to indemnity and contribution from NorthWestern for the costs it has and will incur to investigate and remediate contamination in Operable Unit 1. NorthWestern and BNSF have settled the majority of the dispute for a non-material sum. Any potential remaining claims are not expected to be material.

Yellowstone County Generating Station Air Permit

On October 21, 2021, the Montana Environmental Information Center and the Sierra Club filed a lawsuit in Montana State District Court, against the MDEQ and NorthWestern, alleging that the environmental analysis conducted by MDEQ prior to issuance of the Yellowstone County Generating Station's air quality construction permit was inadequate. On April 4, 2023, the Montana District Court issued an order finding MDEQ's environmental analysis was deficient in not addressing exterior lighting and greenhouse gases and remanded it back to MDEQ to address the deficiencies and vacated the air quality permit pending that remand. As a result of the vacatur of the permit, we paused construction. On June 8, 2023, the Montana District Court granted our motion to stay the order vacating the air quality permit pending the outcome of our notice of appeal with the Montana Supreme Court. Oral argument is scheduled for April 22, 2024 and a determination of the appeal will follow. We recommenced construction in June 2023 and expect the plant to be operational no later than the end of the third quarter 2024. The ultimate resolution of the lawsuit challenging the Yellowstone County Generating Station air quality permit could delay the project and increase costs.

During the litigation of the air permit, Montana House Bill 971 was signed into law, preventing the MDEQ from, except under certain exceptions, evaluating greenhouse gas emissions and corresponding impacts to the climate in environmental reviews of large projects such as coal mines and power plants. On June 1, 2023, the MDEQ issued its supplemental environmental assessment that contained the updated exterior lighting analysis, and the MDEQ indicated that no other analysis was necessary. The comment period concerning the MDEQ’s supplemental air quality permit ended on July 3, 2023. On August 4, 2023, the Montana First Judicial District Court in Held v. State of Montana, a separate case by Montana youths alleging climate damages, issued its order finding House Bill 971 unconstitutional delaying the issuance of the revised Yellowstone County Generating Station's air permit. The Montana Supreme Court granted NorthWestern permission to participate in the Held appeal. The outcome of the Held case could pose additional delays and costs for the Yellowstone County Generating Station.

Other Legal Proceedings

We are also subject to various other legal proceedings, governmental audits and claims that arise in the ordinary course of business. In our opinion, the amount of ultimate liability with respect to these other actions will not materially affect our financial position, results of operations, or cash flows.


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
STATEMENTS OF ACCUMULATED COMPREHENSIVE INCOME, COMPREHENSIVE INCOME, AND HEDGING ACTIVITIES
  1. Report in columns (b),(c),(d) and (e) the amounts of accumulated other comprehensive income items, on a net-of-tax basis, where appropriate.
  2. Report in columns (f) and (g) the amounts of other categories of other cash flow hedges.
  3. For each category of hedges that have been accounted for as "fair value hedges", report the accounts affected and the related amounts in a footnote.
  4. Report data on a year-to-date basis.
Line No.
Item
(a)
Unrealized Gains and Losses on Available-For-Sale Securities
(b)
Minimum Pension Liability Adjustment (net amount)
(c)
Foreign Currency Hedges
(d)
Other Adjustments
(e)
Other Cash Flow Hedges Interest Rate Swaps
(f)
Other Cash Flow Hedges [Specify]
(g)
Totals for each category of items recorded in Account 219
(h)
Net Income (Carried Forward from Page 116, Line 78)
(i)
Total Comprehensive Income
(j)
1
Balance of Account 219 at Beginning of Preceding Year
1,518,461
1,441,981
8,128,038
5,167,596
2
Preceding Quarter/Year to Date Reclassifications from Account 219 to Net Income
(a)
982,991
(e)
452,130
530,861
3
Preceding Quarter/Year to Date Changes in Fair Value
(c)
7,207
7,207
4
Total (lines 2 and 3)
982,991
7,207
452,130
538,068
183,006,620
182,468,552
5
Balance of Account 219 at End of Preceding Quarter/Year
535,470
1,434,774
7,675,908
5,705,664
6
Balance of Account 219 at Beginning of Current Year
535,470
1,434,774
7,675,908
5,705,664
7
Current Quarter/Year to Date Reclassifications from Account 219 to Net Income
(b)
261,851
(f)
452,130
190,279
8
Current Quarter/Year to Date Changes in Fair Value
(d)
2,385
2,385
9
Total (lines 7 and 8)
261,851
2,385
452,130
192,664
194,131,555
194,324,219
10
Balance of Account 219 at End of Current Quarter/Year
273,619
1,437,159
7,223,778
5,513,000


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
FOOTNOTE DATA

(a) Concept: AccumulatedOtherComprehensiveIncomeLossMinimumPensionLiabilityAdjustmentReclassificationsToNetIncomeLoss
Postretirement medical liability adjustment.
(b) Concept: AccumulatedOtherComprehensiveIncomeLossMinimumPensionLiabilityAdjustmentReclassificationsToNetIncomeLoss
Postretirement medical liability adjustment.
(c) Concept: AccumulatedOtherComprehensiveIncomeLossOtherAdjustmentsToComprehensiveIncomeLossChangesInFairValue
Foreign currency translation adjustment.
(d) Concept: AccumulatedOtherComprehensiveIncomeLossOtherAdjustmentsToComprehensiveIncomeLossChangesInFairValue
Foreign currency translation adjustment.
(e) Concept: AccumulatedOtherComprehensiveIncomeLossOtherCashFlowHedgesInterestRateSwapsReclassificationsToNetIncomeLoss
Reclassification of net losses on derivative instruments.
(f) Concept: AccumulatedOtherComprehensiveIncomeLossOtherCashFlowHedgesInterestRateSwapsReclassificationsToNetIncomeLoss
Reclassification of net losses on derivative instruments.

Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
SUMMARY OF UTILITY PLANT AND ACCUMULATED PROVISIONS FOR DEPRECIATION. AMORTIZATION AND DEPLETION

Report in Column (c) the amount for electric function, in column (d) the amount for gas function, in column (e), (f), and (g) report other (specify) and in column (h) common function.

Line No.
Classification
(a)
Total Company For the Current Year/Quarter Ended
(b)
Electric
(c)
Gas
(d)
Other (Specify)
(e)
Other (Specify)
(f)
Other (Specify)
(g)
Common
(h)
1
UtilityPlantAbstract
UTILITY PLANT
2
UtilityPlantInServiceAbstract
In Service
3
UtilityPlantInServiceClassified
Plant in Service (Classified)
7,246,717,986
5,534,182,214
1,446,633,922
(d)
1,547,776
264,354,074
4
UtilityPlantInServicePropertyUnderCapitalLeases
Property Under Capital Leases
41,127,257
(e)
40,209,537
(f)
917,720
5
UtilityPlantInServicePlantPurchasedOrSold
Plant Purchased or Sold
6
UtilityPlantInServiceCompletedConstructionNotClassified
Completed Construction not Classified
7
UtilityPlantInServiceExperimentalPlantUnclassified
Experimental Plant Unclassified
4,798,750
4,798,750
8
UtilityPlantInServiceClassifiedAndUnclassified
Total (3 thru 7)
7,292,643,993
5,538,980,964
1,446,633,922
1,547,776
40,209,537
917,720
264,354,074
9
UtilityPlantLeasedToOthers
Leased to Others
10
UtilityPlantHeldForFutureUse
Held for Future Use
4,140,227
4,110,361
29,866
11
ConstructionWorkInProgress
Construction Work in Progress
358,401,452
314,784,647
31,789,634
11,827,171
12
UtilityPlantAcquisitionAdjustment
Acquisition Adjustments
686,328,435
(a)
686,328,435
13
UtilityPlantAndConstructionWorkInProgress
Total Utility Plant (8 thru 12)
8,341,514,107
6,544,204,407
1,478,453,422
1,547,776
40,209,537
917,720
276,181,245
14
AccumulatedProvisionForDepreciationAmortizationAndDepletionOfPlantUtility
Accumulated Provisions for Depreciation, Amortization, & Depletion
2,874,902,417
2,206,158,106
557,399,271
1,127,274
35,183,325
75,034,441
15
UtilityPlantNet
Net Utility Plant (13 less 14)
5,466,611,690
4,338,046,301
921,054,151
420,502
5,026,212
917,720
201,146,804
16
DetailOfAccumulatedProvisionsForDepreciationAmortizationAndDepletionAbstract
DETAIL OF ACCUMULATED PROVISIONS FOR DEPRECIATION, AMORTIZATION AND DEPLETION
17
AccumulatedProvisionForDepreciationAmortizationAndDepletionUtilityPlantInServiceAbstract
In Service:
18
DepreciationUtilityPlantInService
Depreciation
2,579,322,998
1,990,020,890
498,438,283
1,127,274
35,183,325
54,553,226
19
AmortizationAndDepletionOfProducingNaturalGasLandAndLandRightsutilityPlantInService
Amortization and Depletion of Producing Natural Gas Land and Land Rights
51,927,733
51,927,733
20
AmortizationOfUndergroundStorageLandAndLandRightsutilityPlantInService
Amortization of Underground Storage Land and Land Rights
21
AmortizationOfOtherUtilityPlantUtilityPlantInService
Amortization of Other Utility Plant
54,788,147
(b)
27,273,677
7,033,255
20,481,215
22
DepreciationAmortizationAndDepletionUtilityPlantInService
Total in Service (18 thru 21)
2,686,038,878
2,017,294,567
557,399,271
1,127,274
35,183,325
75,034,441
23
DepreciationAmortizationAndDepletionUtilityPlantLeasedToOthersAbstract
Leased to Others
24
DepreciationUtilityPlantLeasedToOthers
Depreciation
25
AmortizationAndDepletionUtilityPlantLeasedToOthers
Amortization and Depletion
26
DepreciationAmortizationAndDepletionUtilityPlantLeasedToOthers
Total Leased to Others (24 & 25)
27
DepreciationAndAmortizationUtilityPlantHeldForFutureUseAbstract
Held for Future Use
28
DepreciationUtilityPlantHeldForFutureUse
Depreciation
29
AmortizationUtilityPlantHeldForFutureUse
Amortization
30
DepreciationAndAmortizationUtilityPlantHeldForFutureUse
Total Held for Future Use (28 & 29)
31
AbandonmentOfLeases
Abandonment of Leases (Natural Gas)
32
AmortizationOfPlantAcquisitionAdjustment
Amortization of Plant Acquisition Adjustment
188,863,539
(c)
188,863,539
33
AccumulatedProvisionForDepreciationAmortizationAndDepletionOfPlantUtility
Total Accum Prov (equals 14) (22,26,30,31,32)
2,874,902,417
2,206,158,106
557,399,271
1,127,274
35,183,325
75,034,441


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
FOOTNOTE DATA

(a) Concept: UtilityPlantAcquisitionAdjustment
Acquisition Adjustments of $686,328,435 consists of $656,318,593 for Montana Operations and $30,009,842 for South Dakota Operations.
(b) Concept: AmortizationOfOtherUtilityPlantUtilityPlantInService
Amortization of Other South Dakota Electric Plant was $270,599 and $2,387 for 2023 and 2022, respectively.
Amortization of Other Montana Electric Plant was $27,003,078 and $24,207,683 for 2023 and 2022, respectively.
(c) Concept: AmortizationOfPlantAcquisitionAdjustment
Amortization of Plant Acquisition Adjustments of $188,863,539 consist of $178,960,291 for Montana Operations and $9,903,248 for South Dakota Operations.
(d) Concept: UtilityPlantInServiceClassified
This column represents regulated propane
(e) Concept: UtilityPlantInServicePropertyUnderCapitalLeases
This column represents an electric default supply capacity and energy sales agreement classified as a capital lease.
(f) Concept: UtilityPlantInServicePropertyUnderCapitalLeases
This column represents our right of use (operating lease) assets.

Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
NUCLEAR FUEL MATERIALS (Account 120.1 through 120.6 and 157)
  1. Report below the costs incurred for nuclear fuel materials in process of fabrication, on hand, in reactor, and in cooling; owned by the respondent.
  2. If the nuclear fuel stock is obtained under leasing arrangements, attach a statement showing the amount of nuclear fuel leased, the quantity used and quantity on hand, and the costs incurred under such leasing arrangements.
Line No.
Description of item
(a)
Balance Beginning of Year
(b)
Changes during Year Additions
(c)
Changes during Year Amortization
(d)
Changes during Year Other Reductions (Explain in a footnote)
(e)
Balance End of Year
(f)
1
Nuclear Fuel in process of Refinement, Conv, Enrichment & Fab (120.1)
2
Fabrication
3
Nuclear Materials
4
Allowance for Funds Used during Construction
5
(Other Overhead Construction Costs, provide details in footnote)
6
SUBTOTAL (Total 2 thru 5)
7
Nuclear Fuel Materials and Assemblies
8
In Stock (120.2)
9
In Reactor (120.3)
10
SUBTOTAL (Total 8 & 9)
11
Spent Nuclear Fuel (120.4)
12
Nuclear Fuel Under Capital Leases (120.6)
13
(Less) Accum Prov for Amortization of Nuclear Fuel Assem (120.5)
14
TOTAL Nuclear Fuel Stock (Total 6, 10, 11, 12, less 13)
15
Estimated Net Salvage Value of Nuclear Materials in Line 9
16
Estimated Net Salvage Value of Nuclear Materials in Line 11
17
Est Net Salvage Value of Nuclear Materials in Chemical Processing
18
Nuclear Materials held for Sale (157)
19
Uranium
20
Plutonium
21
Other (Provide details in footnote)
22
TOTAL Nuclear Materials held for Sale (Total 19, 20, and 21)


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
ELECTRIC PLANT IN SERVICE (Account 101, 102, 103 and 106)
  1. Report below the original cost of electric plant in service according to the prescribed accounts.
  2. In addition to Account 101, Electric Plant in Service (Classified), this page and the next include Account 102, Electric Plant Purchased or Sold; Account 103, Experimental Electric Plant Unclassified; and Account 106, Completed Construction Not Classified-Electric.
  3. Include in column (c) or (d), as appropriate, corrections of additions and retirements for the current or preceding year.
  4. For revisions to the amount of initial asset retirement costs capitalized, included by primary plant account, increases in column (c) additions and reductions in column (e) adjustments.
  5. Enclose in parentheses credit adjustments of plant accounts to indicate the negative effect of such accounts.
  6. Classify Account 106 according to prescribed accounts, on an estimated basis if necessary, and include the entries in column (c). Also to be included in column (c) are entries for reversals of tentative distributions of the prior year reported in column (b). Likewise, if the respondent has a significant amount of plant retirements which have not been classified to primary accounts at the end of the year, include in column (d) a tentative distribution of such retirements, on an estimated basis, with appropriate contra entry to the account for accumulated depreciation provision. Include also in column (d) distributions of these tentative classifications in columns (c) and (d), including the reversals of the prior years tentative account distributions of these amounts. Careful observance of the above instructions and the texts of Accounts 101 and 106 will avoid serious omissions of the reported amount of respondent’s plant actually in service at end of year.
  7. Show in column (f) reclassifications or transfers within utility plant accounts. Include also in column (f) the additions or reductions of primary account classifications arising from distribution of amounts initially recorded in Account 102, include in column (e) the amounts with respect to accumulated provision for depreciation, acquisition adjustments, etc., and show in column (f) only the offset to the debits or credits distributed in column (f) to primary account classifications.
  8. For Account 399, state the nature and use of plant included in this account and if substantial in amount submit a supplementary statement showing subaccount classification of such plant conforming to the requirement of these pages.
  9. For each amount comprising the reported balance and changes in Account 102, state the property purchased or sold, name of vendor or purchase, and date of transaction. If proposed journal entries have been filed with the Commission as required by the Uniform System of Accounts, give also date.
Line No.
Account
(a)
Balance Beginning of Year
(b)
Additions
(c)
Retirements
(d)
Adjustments
(e)
Transfers
(f)
Balance at End of Year
(g)
1
1. INTANGIBLE PLANT
2
(301) Organization
(a)
19,995
19,995
3
(302) Franchise and Consents
(b)
20,247,608
1,232,101
21,479,709
4
(303) Miscellaneous Intangible Plant
12,251,711
3,658,800
2,662,554
18,573,065
5
TOTAL Intangible Plant (Enter Total of lines 2, 3, and 4)
32,519,314
4,890,901
2,662,554
40,072,769
6
2. PRODUCTION PLANT
7
A. Steam Production Plant
8
(310) Land and Land Rights
812,637
812,637
9
(311) Structures and Improvements
55,522,863
488,271
55,381
55,955,753
10
(312) Boiler Plant Equipment
244,887,717
1,615,237
2,633,055
243,869,899
11
(313) Engines and Engine-Driven Generators
12
(314) Turbogenerator Units
48,867,033
1,094,959
1,250,032
48,711,960
13
(315) Accessory Electric Equipment
15,657,364
36,622
472,785
15,221,201
14
(316) Misc. Power Plant Equipment
26,048,047
219,867
35,757
26,232,157
15
(317) Asset Retirement Costs for Steam Production
22,463,670
913,721
23,377,391
16
TOTAL Steam Production Plant (Enter Total of lines 8 thru 15)
414,259,331
4,368,677
4,447,010
414,180,998
17
B. Nuclear Production Plant
18
(320) Land and Land Rights
19
(321) Structures and Improvements
20
(322) Reactor Plant Equipment
21
(323) Turbogenerator Units
22
(324) Accessory Electric Equipment
23
(325) Misc. Power Plant Equipment
24
(326) Asset Retirement Costs for Nuclear Production
25
TOTAL Nuclear Production Plant (Enter Total of lines 18 thru 24)
26
C. Hydraulic Production Plant
27
(330) Land and Land Rights
28
(331) Structures and Improvements
5,941,678
16,738
5,958,416
29
(332) Reservoirs, Dams, and Waterways
126,687,963
3,404,837
42,238
130,050,562
30
(333) Water Wheels, Turbines, and Generators
195,625,955
15,693,790
16,157,945
195,161,800
31
(334) Accessory Electric Equipment
176,785,446
13,493,970
713,244
189,566,172
32
(335) Misc. Power Plant Equipment
94,377,564
490,305
94,867,869
33
(336) Roads, Railroads, and Bridges
20,725,764
42,624
20,768,388
34
(337) Asset Retirement Costs for Hydraulic Production
2,947,096
122,188
3,069,284
35
TOTAL Hydraulic Production Plant (Enter Total of lines 27 thru 34)
623,091,466
33,264,452
16,913,427
639,442,491
36
D. Other Production Plant
37
(340) Land and Land Rights
3,901,868
178,696
4,080,564
38
(341) Structures and Improvements
86,250,639
305
617,605
85,633,339
39
(342) Fuel Holders, Products, and Accessories
26,534,378
20,580
26,513,798
40
(343) Prime Movers
230,850,977
21,003,307
33,810,850
218,043,434
41
(344) Generators
143,520,064
143,520,064
42
(345) Accessory Electric Equipment
27,080,006
55,169
27,024,837
43
(346) Misc. Power Plant Equipment
51,794,908
41,710
130,597
51,706,021
44
(347) Asset Retirement Costs for Other Production
5,038,356
5,038,356
44.1
(348) Energy Storage Equipment - Production
45
TOTAL Other Prod. Plant (Enter Total of lines 37 thru 44)
574,971,196
21,224,018
34,634,801
561,560,413
46
TOTAL Prod. Plant (Enter Total of lines 16, 25, 35, and 45)
1,612,321,993
58,857,147
55,995,238
1,615,183,902
47
3. Transmission Plant
48
(350) Land and Land Rights
41,854,653
2,986,050
44,840,703
48.1
(351) Energy Storage Equipment - Transmission
49
(352) Structures and Improvements
61,332,819
11,972,290
423,877
4,266,936
77,148,168
50
(353) Station Equipment
440,406,499
46,051,449
7,741,360
4,067,306
474,649,282
51
(354) Towers and Fixtures
30,385,864
254,278
30,640,142
52
(355) Poles and Fixtures
519,110,409
40,943,138
2,096,507
76,600
557,880,440
53
(356) Overhead Conductors and Devices
212,937,523
6,421,698
433,279
7,211
218,933,153
54
(357) Underground Conduit
778,680
778,680
55
(358) Underground Conductors and Devices
6,640,975
1,384
26,615
6,668,974
56
(359) Roads and Trails
4,043,372
4,043,372
57
(359.1) Asset Retirement Costs for Transmission Plant
58
TOTAL Transmission Plant (Enter Total of lines 48 thru 57)
1,317,490,794
108,630,287
10,695,023
156,856
1,415,582,914
59
4. Distribution Plant
60
(360) Land and Land Rights
15,371,502
51,702
4,106
15,419,098
61
(361) Structures and Improvements
39,975,630
3,479,455
368,182
2,626,241
45,713,144
62
(362) Station Equipment
293,557,260
26,178,151
5,315,008
2,883,909
311,536,494
63
(363) Energy Storage Equipment – Distribution
64
(364) Poles, Towers, and Fixtures
431,334,582
21,677,454
1,486,918
90,886
451,616,004
65
(365) Overhead Conductors and Devices
172,262,323
7,696,009
328,759
179,629,573
66
(366) Underground Conduit
179,237,133
14,864,225
62,731
194,038,627
67
(367) Underground Conductors and Devices
328,626,662
20,217,421
831,739
348,012,344
68
(368) Line Transformers
301,713,243
24,026,371
2,216,133
323,523,481
69
(369) Services
196,311,139
13,995,005
279,041
210,027,103
70
(370) Meters
90,993,396
17,724,773
6,995,635
101,722,534
71
(371) Installations on Customer Premises
746,087
10,915
21,640
735,362
72
(372) Leased Property on Customer Premises
73
(373) Street Lighting and Signal Systems
91,192,236
4,941,140
2,124,970
94,008,406
74
(374) Asset Retirement Costs for Distribution Plant
75
TOTAL Distribution Plant (Enter Total of lines 60 thru 74)
2,141,321,193
154,862,621
20,034,862
166,782
2,275,982,170
76
5. REGIONAL TRANSMISSION AND MARKET OPERATION PLANT
77
(380) Land and Land Rights
78
(381) Structures and Improvements
79
(382) Computer Hardware
80
(383) Computer Software
81
(384) Communication Equipment
82
(385) Miscellaneous Regional Transmission and Market Operation Plant
83
(386) Asset Retirement Costs for Regional Transmission and Market Oper
84
TOTAL Transmission and Market Operation Plant (Total lines 77 thru 83)
85
6. General Plant
86
(389) Land and Land Rights
796,461
1,320
795,141
87
(390) Structures and Improvements
12,542,442
35,793
118,099
12,460,136
88
(391) Office Furniture and Equipment
1,216,438
1,743,075
407,757
2,551,756
89
(392) Transportation Equipment
82,820,012
5,317,518
3,027,609
85,109,921
90
(393) Stores Equipment
1,143,158
48,010
1,191,168
91
(394) Tools, Shop and Garage Equipment
12,583,614
841,767
238,440
13,186,941
92
(395) Laboratory Equipment
1,033,178
1,033,178
93
(396) Power Operated Equipment
7,391,873
655,874
67,546
7,980,201
94
(397) Communication Equipment
52,805,248
9,121,036
1,013,516
16,538
60,929,306
95
(398) Miscellaneous Equipment
2,122,711
2,122,711
96
SUBTOTAL (Enter Total of lines 86 thru 95)
174,455,135
17,763,073
4,874,287
16,538
187,360,459
97
(399) Other Tangible Property
98
(399.1) Asset Retirement Costs for General Plant
99
TOTAL General Plant (Enter Total of lines 96, 97, and 98)
174,455,135
17,763,073
4,874,287
16,538
187,360,459
100
TOTAL (Accounts 101 and 106)
5,278,108,429
345,004,029
91,599,410
2,669,166
5,534,182,214
101
(102) Electric Plant Purchased (See Instr. 8)
102
(Less) (102) Electric Plant Sold (See Instr. 8)
103
(103) Experimental Plant Unclassified
4,244,173
554,577
4,798,750
104
TOTAL Electric Plant in Service (Enter Total of lines 100 thru 103)
5,282,352,602
345,558,606
91,599,410
2,669,166
5,538,980,964


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
FOOTNOTE DATA

(a) Concept: Organization
Montana operations

Line Account Beginning of
Year
Additions Retirements Adjustments Transfers End of Year
No. (a) (b) (c) (d) (e) (f) (g)
1 1. INTANGIBLE PLANT
2 (301) Organization 19,995  —  —  —  —  19,995 
3 (302) Franchises and Consents 20,247,608  1,232,101  —  —  —  21,479,709 
4 (303) Miscellaneous Intangible Plant 12,243,407  3,658,800  —  705,518  16,607,725 
5 TOTAL Intangible Plant (Enter Total of lines 2, 3, and4) 32,511,010  4,890,901  —  —  705,518  38,107,429 
6 2. PRODUCTION PLANT
7 A. Steam Production Plant
8 (310) Land and Land Rights 446,126  —  —  —  —  446,126 
9 (311) Structures and Improvements 28,250,520  4,061  40,633  —  —  28,213,948 
10 (312) Boiler Plant Equipment 44,982,542  27,910  2,418,216  —  —  42,592,236 
11 (313) Engines and Engine-Driven Generators —  —  —  —  —  — 
12 (314) Turbogenerator Units 22,255,086  —  1,185,625  —  —  21,069,461 
13 (315) Accessory Electric Equipment 2,519,145  23,075  465,747  —  —  2,076,473 
14 (316) Misc. Power Plant Equipment 22,947,674  —  —  —  —  22,947,674 
15 (317) Asset Retirement Costs for Steam 19,799,959  1,553,530  —  —  —  21,353,489 
16 TOTAL Steam Production Plant (Enter Total of lines 8 thru 14) 141,201,052  1,608,576  4,110,221  —  —  138,699,407 
17 B. Nuclear Production Plant
18 (320) Land and Land Rights —  —  —  —  —  — 
19 (321) Structures and Improvements —  —  —  —  —  — 
20 (322) Reactor Plant Equipment —  —  —  —  —  — 
21 (323) Turbogenerator Units —  —  —  —  —  — 
22 (324) Accessory Electric Equipment —  —  —  —  —  — 
23 (325) Misc. Power Plant Equipment —  —  —  —  —  — 
24 TOTAL Nuclear Production Plant (Enter Total of lines 17 thru 22) —  —  —  —  —  — 
25 C. Hydraulic Production Plant
26 (330) Land and Land Rights 5,941,678  16,738  —  —  —  5,958,416 
27 (331) Structures and Improvements 126,687,963  3,404,837  42,238  —  —  130,050,562 
28 (332) Reservoirs, Dams, and Waterways 195,625,955  15,693,790  16,157,945  —  —  195,161,800 
29 (333) Water Wheels, Turbines, and Generators 176,785,446  13,493,970  713,244  —  —  189,566,172 
30 (334) Accessory Electric Equipment 94,377,564  490,305  —  —  —  94,867,869 
31 (335) Misc. Power Plant Equipment 20,725,764  42,624  —  —  —  20,768,388 
32 (336) Roads, Railroads, and Bridges 2,947,096  122,188  —  —  —  3,069,284 
33
TOTAL Hydraulic Production Plant (Enter Total of lines 25 thru 31)
623,091,466  33,264,452  16,913,427  —  —  639,442,491 
34 D. Other Production Plant
35 (340) Land and Land Rights 3,819,385  —  —  —  —  3,819,385 
36 (341) Structures and Improvements 59,449,471  —  —  —  —  59,449,471 
37 (342) Fuel Holders, Products, and
Accessories
21,230,045  —  —  —  —  21,230,045 
38 (343) Prime Movers 102,231,898  20,405,413  32,076,255  —  —  90,561,056 
39 (344) Generators 55,657,436  —  —  —  —  55,657,436 
40 (345) Accessory Electric Equipment 19,164,004  —  —  —  —  19,164,004 
41 (346) Misc. Power Plant Equipment 29,091,023  —  —  —  —  29,091,023 
42
(347) Asset Retirement Costs for Other
Production
3,686,815  —  —  —  —  3,686,815 
43
TOTAL Other Production Plant (Enter Total of lines 34 thru 40)
294,330,077  20,405,413  32,076,255  —  —  282,659,235 
44
TOTAL Production Plant (Enter Total of lines 15, 23, 32, and 41)
1,058,622,595  55,278,441  53,099,903  —  —  1,060,801,133 
45 3. TRANSMISSION PLANT
46 (350) Land and Land Rights 40,120,055  2,847,269  —  —  —  42,967,324 
47 (352) Structures and Improvements 48,939,329  10,826,091  423,877  —  4,266,936  63,608,479 
48 (353) Station Equipment 338,651,187  37,736,625  7,438,059  —  (3,948,155) 365,001,598 
49 (354) Towers and Fixtures 30,385,864  254,278  —  —  —  30,640,142 
50 (355) Poles and Fixtures 457,923,471  38,429,145  1,965,010  —  (76,600) 494,311,006 
51 (356) Overhead Conductors and Devices 179,733,447  6,037,165  418,809  —  7,211  185,359,014 
52 (357) Underground Conduit 137,878  —  —  —  —  137,878 
53 (358) Underground Conductors and Devices 1,935,349  —  —  —  26,615  1,961,964 
54 (359) Roads and Trails 4,043,372  —  —  —  —  4,043,372 
55
TOTAL Transmission Plant (Enter Total of lines 44 thru 52)
1,101,869,952  96,130,573  10,245,755  —  276,007  1,188,030,777 
56 4. DISTRIBUTION PLANT
57 (360) Land and Land Rights 14,731,957  51,702  4,106  —  —  14,779,553 
58 (361) Structures and Improvements 38,491,604  3,430,707  368,182  —  2,626,241  44,180,370 
59 (362) Station Equipment 246,414,841  24,147,880  5,036,114  —  (3,003,060) 262,523,547 
60 (363) Storage Battery Equipment —  —  —  —  —  — 
61 (364) Poles, Towers, and Fixtures 372,403,164  18,680,311  1,082,768  —  90,886  390,091,593 
62 (365) Overhead Conductors and Devices 150,470,917  5,604,519  74,577  —  —  156,000,859 
63 (366) Underground Conduit 168,176,646  14,172,551  62,731  —  —  182,286,466 
64 (367) Underground Conductors and Devices 265,189,715  17,160,624  289,869  —  —  282,060,470 
65 (368) Line Transformers 258,401,661  21,210,620  2,216,133  —  —  277,396,148 
66 (369) Services 173,892,685  12,772,457  129,116  —  —  186,536,026 
67 (370) Meters 76,988,468  16,932,118  6,930,787  —  —  86,989,799 
68 (371) Installations on Customer Premises —  —  —  —  —  — 
69 (372) Leased Property on Customer Premises —  —  —  —  —  — 
70 (373&388) Street Lighting and Signal Systems 81,731,152  1,771,644  404,703  —  —  83,098,093 
71
(374) Asset Retirement Costs for Distribution Plant
—  —  —  —  —  — 
72
TOTAL Distribution Plant (Enter Total of lines 55 thru 68)
1,846,892,810  135,935,133  16,599,086  —  (285,933) 1,965,942,924 
73 5. GENERAL PLANT
74 (389) Land and Land Rights 689,633  —  —  —  —  689,633 
75 (390) Structures and Improvements 10,698,488  —  73,400  —  —  10,625,088 
76 (391) Office Furniture and Equipment 1,209,368  1,662,490  405,191  —  —  2,466,667 
77 (392) Transportation Equipment 65,753,018  4,564,891  2,491,507  —  —  67,826,402 
78 (393) Stores Equipment 1,143,158  11,950  —  —  —  1,155,108 
79 (394) Tools, Shop and Garage Equipment 10,567,559  684,982  156,699  —  —  11,095,842 
80 (395) Laboratory Equipment 1,033,178  —  —  —  —  1,033,178 
81 (396) Power Operated Equipment 6,542,837  565,924  67,546  —  —  7,041,215 
82 (397) Communication Equipment 49,700,312  8,843,727  310,886  —  16,539  58,249,692 
83 (398) Miscellaneous Equipment 2,122,710  —  —  —  —  2,122,710 
84 SUBTOTAL (Enter Total of lines 71 thru 80) 149,460,261  16,333,964  3,505,229  —  16,539  162,305,535 
85 (399) Other Tangible Property —  —  —  —  —  — 
86
TOTAL General Plant (Enter Total of lines 81 and 82)
149,460,261  16,333,964  3,505,229  —  16,539  162,305,535 
87 TOTAL (Accounts 101 and 106) 4,189,356,628  308,569,012  83,449,973  —  712,131  4,415,187,798 
88 (102) Electric Plant Purchased (See Instr. 8) —  —  — 
89 (Less) (102) Electric Plant Sold (See Instr. 8) —  —  — 
90 (103) Experimental Plant Unclassified 4,244,173  554,577  —  —  —  4,798,750 
91 TOTAL Electric Plant in Service(Enter Total of lines 84 thru 87) 4,193,600,801  309,123,589  83,449,973  —  712,131  4,419,986,548 
(b) Concept: FranchisesAndConsents
South Dakota Operations

Line Account Beginning of
Year
Additions Retirement
Adjustments Transfers End of Year Plant
No. (a) (b) (c) (d) (e) (f) (g) Acct
1 1. INTANGIBLE PLANT
2 (301) Organization —  —  —  —  —  —  (301)
3 (302) Franchises and Consents —  —  —  —  —  —  (302)
4 (303) Miscellaneous Intangible Plant 8,304  —  —  1,957,036  1,965,340  (303)
5 TOTAL Intangible Plant (Enter Total of lines 2, 3, and4) 8,304  —  —  1,957,036  1,965,340 
6 2. PRODUCTION PLANT — 
7 A. Steam Production Plant — 
8 (310) Land and Land Rights 366,511  —  —  —  —  366,511  (310)
9 (311) Structures and Improvements 27,272,343  484,210  14,748  —  —  27,741,805  (311)
10 (312) Boiler Plant Equipment 199,905,175  1,587,327  214,839  —  —  201,277,663  (312)
11 (313) Engines and Engine-Driven Generators —  —  —  —  —  —  (313)
12 (314) Turbogenerator Units 26,611,947  1,094,959  64,407  —  —  27,642,499  (314)
13 (315) Accessory Electric Equipment 13,138,219  13,547  7,038  —  —  13,144,728  (315)
14 (316) Misc. Power Plant Equipment 3,100,373  219,867  35,756  —  —  3,284,484  (316)
15 (317) Asset Retirement Costs for Steam 2,663,711  (639,809) —  —  —  2,023,902 
16 TOTAL Steam Production Plant (Enter Total of lines 8 thru 14) 273,058,279  2,760,101  336,788  —  —  275,481,592 
17 B. Nuclear Production Plant
18 (320) Land and Land Rights —  —  —  —  —  —  (320)
19 (321) Structures and Improvements —  —  —  —  —  —  (321)
20 (322) Reactor Plant Equipment —  —  —  —  —  —  (322)
21 (323) Turbogenerator Units —  —  —  —  —  —  (323)
22 (324) Accessory Electric Equipment —  —  —  —  —  —  (324)
23 (325) Misc. Power Plant Equipment —  —  —  —  —  —  (325)
24 TOTAL Nuclear Production Plant (Enter Total of lines 17 thru 22) —  —  —  —  —  — 
25 C. Hydraulic Production Plant
26 (330) Land and Land Rights —  —  —  —  (330)
27 (331) Structures and Improvements —  —  —  —  —  (331)
28 (332) Reservoirs, Dams, and Waterways —  —  —  —  (332)
29 (333) Water Wheels, Turbines, and Generators —  —  —  —  (333)
30 (334) Accessory Electric Equipment —  —  —  —  (334)
31 (335) Misc. Power Plant Equipment —  —  —  —  (335)
32 (336) Roads, Railroads, and Bridges —  —  —  —  (336)
33
TOTAL Hydraulic Production Plant (Enter Total of lines 25 thru 31)
—  —  —  —  —  — 
34 D. Other Production Plant
35 (340) Land and Land Rights 82,483  178,696  —  —  —  261,179  (340)
36 (341) Structures and Improvements 26,801,168  305  617,605  —  —  26,183,868  (341)
37 (342) Fuel Holders, Products, and
Accessories
5,304,333  —  20,580  —  —  5,283,753  (342)
38 (343) Prime Movers 128,619,079  597,894  1,734,595  —  —  127,482,378  (343)
39 (344) Generators 87,862,628  —  —  —  —  87,862,628  (344)
40 (345) Accessory Electric Equipment 7,916,002  —  55,169  —  —  7,860,833  (345)
41 (346) Misc. Power Plant Equipment 22,703,885  41,710  130,597  —  —  22,614,998  (346)
42
(347) Asset Retirement Costs for Other Production
1,351,541  —  —  —  —  1,351,541 
43
TOTAL Other Production Plant (Enter Total of lines 34 thru 40)
280,641,119  818,605  2,558,546  —  —  278,901,178 
44
TOTAL Production Plant (Enter Total of lines 15, 23, 32, and 41)
553,699,398  3,578,706  2,895,334  —  —  554,382,770 
45 3. TRANSMISSION PLANT
46 (350) Land and Land Rights 1,734,599  138,781  —  —  —  1,873,380  (350)
47 (352) Structures and Improvements 12,393,490  1,146,199  —  —  —  13,539,689  (352)
48 (353) Station Equipment 101,755,312  8,314,824  303,301  —  (119,151) 109,647,684  (353)
49 (354) Towers and Fixtures —  —  —  —  —  —  (354)
50 (355) Poles and Fixtures 61,186,936  2,513,991  131,497  —  —  63,569,430  (355)
51 (356) Overhead Conductors and Devices 33,204,076  384,533  14,470  —  —  33,574,139  (356)
52 (357) Underground Conduit 640,802  —  —  —  —  640,802  (357)
53 (358) Underground Conductors and Devices 4,705,625  1,384  —  —  —  4,707,009  (358)
54 (359) Roads and Trails —  —  —  —  —  (359)
55
TOTAL Transmission Plant (Enter Total of lines 44 thru 52)
215,620,840  12,499,712  449,268  —  (119,151) 227,552,133 
56 4. DISTRIBUTION PLANT
57 (360) Land and Land Rights 639,546  —  —  —  —  639,546  (360)
58 (361) Structures and Improvements 1,484,027  48,748  —  —  —  1,532,775  (361)
59 (362) Station Equipment 47,142,419  2,030,271  278,894  —  119,151  49,012,947  (362)
60 (363) Storage Battery Equipment —  —  —  —  —  —  (363)
61 (364) Poles, Towers, and Fixtures 58,931,418  2,997,143  404,150  —  —  61,524,411  (364)
62 (365) Overhead Conductors and Devices 21,791,407  2,091,490  254,182  —  —  23,628,715  (365)
63 (366) Underground Conduit 11,060,486  691,674  —  —  —  11,752,160  (366)
64 (367) Underground Conductors and Devices 63,436,947  3,056,797  541,870  —  —  65,951,874  (367)
65 (368) Line Transformers 43,311,582  2,815,751  —  —  —  46,127,333  (368)
66 (369) Services 22,418,454  1,222,548  149,925  —  —  23,491,077  (369)
67 (370) Meters 14,004,928  792,655  64,848  —  —  14,732,735  (370)
68 (371) Installations on Customer Premises 746,086  10,915  21,640  —  —  735,361  (371)
69 (372) Leased Property on Customer Premises —  —  —  —  —  —  (372)
70 (373&388) Street Lighting and Signal Systems 9,461,084  3,169,496  1,720,267  —  —  10,910,313  (373)
71
(374) Asset Retirement Costs for Distribution Plant
—  —  —  —  —  —  (374)
72
TOTAL Distribution Plant (Enter Total of lines 55 thru 68)
294,428,384  18,927,488  3,435,776  —  119,151  310,039,247 
73 5. GENERAL PLANT
74 (389) Land and Land Rights 106,828  —  1,320  —  —  105,508  (389)
75 (390) Structures and Improvements 1,843,955  35,793  44,699  —  —  1,835,049  (390)
76 (391) Office Furniture and Equipment 7,070  80,585  2,566  —  —  85,089  (391)
77 (392) Transportation Equipment 17,066,995  752,627  536,102  —  —  17,283,520  (392)
78 (393) Stores Equipment —  36,060  —  —  —  36,060  (393)
79 (394) Tools, Shop and Garage Equipment 2,016,056  156,785  81,741  —  —  2,091,100  (394)
80 (395) Laboratory Equipment —  —  —  —  —  —  (395)
81 (396) Power Operated Equipment 849,036  89,951  —  —  —  938,987  (396)
82 (397) Communication Equipment 3,104,934  277,311  702,632  —  —  2,679,613  (397)
83 (398) Miscellaneous Equipment —  —  —  —  —  —  (398)
84 SUBTOTAL (Enter Total of lines 71 thru 80) 24,994,874  1,429,112  1,369,060  —  —  25,054,926 
85 (399) Other Tangible Property —  —  —  —  —  —  (399)
86
TOTAL General Plant (Enter Total of lines 81 and 82)
24,994,874  1,429,112  1,369,060  —  —  25,054,926 
87 TOTAL (Accounts 101 and 106) 1,088,751,800  36,435,018  8,149,438  —  1,957,036  1,118,994,416 
88 (102) Electric Plant Purchased (See Instr. 8) —  —  —  (102)
89 (Less) (102) Electric Plant Sold (See Instr. 8) —  —  —  —  (102)
90 (103) Experimental Plant Unclassified —  —  —  (103)
91 TOTAL Electric Plant in Service(Enter Total of lines 84 thru 87) 1,088,751,800  36,435,018  8,149,438  —  1,957,036  1,118,994,416 

Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
ELECTRIC PLANT LEASED TO OTHERS (Account 104)
Line No.
LesseeName
Name of Lessee
(a)
IndicationOfAssociatedCompany
* (Designation of Associated Company)
(b)
LeaseDescription
Description of Property Leased
(c)
CommissionAuthorization
Commission Authorization
(d)
ExpirationDateOfLease
Expiration Date of Lease
(e)
ElectricPlantLeasedToOthers
Balance at End of Year
(f)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
TOTAL


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
ELECTRIC PLANT HELD FOR FUTURE USE (Account 105)
  1. Report separately each property held for future use at end of the year having an original cost of $250,000 or more. Group other items of property held for future use.
  2. For property having an original cost of $250,000 or more previously used in utility operations, now held for future use, give in column (a), in addition to other required information, the date that utility use of such property was discontinued, and the date the original cost was transferred to Account 105.
Line No.
ElectricPlantHeldForFutureUseDescription
Description and Location of Property
(a)
ElectricPlantPropertyClassifiedAsHeldForFutureUseOriginalDate
Date Originally Included in This Account
(b)
ElectricPlantPropertyClassifiedAsHeldForFutureUseExpectedUseInServiceDate
Date Expected to be used in Utility Service
(c)
ElectricPlantHeldForFutureUse
Balance at End of Year
(d)
1 Land and Rights:
2
(a)
Montana Operations:
3
Townsend Transmission Sub site
01/01/2011
12/01/2027
1,763,378
4
Missoula Miller Creek Sub site
01/01/2001
04/01/2024
625,904
5
Billings Metra Sub Site
07/01/2019
12/01/2028
595,346
6
Minor Projects (Less than $250,000 - 18 items)
1,125,733
21 Other Property:
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47 TOTAL
4,110,361


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
FOOTNOTE DATA

(a) Concept: ElectricPlantHeldForFutureUseDescription
This schedule represents Montana Operations only.

Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
CONSTRUCTION WORK IN PROGRESS - - ELECTRIC (Account 107)
  1. Report below descriptions and balances at end of year of projects in process of construction (107).
  2. Show items relating to "research, development, and demonstration" projects last, under a caption Research, Development, and Demonstrating (see Account 107 of the Uniform System of Accounts).
  3. Minor projects (5% of the Balance End of the Year for Account 107 or $1,000,000, whichever is less) may be grouped.
Line No.
ConstructionWorkInProgressProjectDescription
Description of Project
(a)
ConstructionWorkInProgress
Construction work in progress - Electric (Account 107)
(b)
1
MONTANA
2
Yellowstone Gen Station
226,280,753
3
Cochrane U2 Turbine Upgrade
7,292,149
4
Bozeman Division Electric-Cap Blnkt Growth
5,455,498
5
Miller Crk Rebuild
5,013,778
6
Cochrane U2 Gen Restack & Rewind
4,041,523
7
AMI Metering & Infrastructure
3,432,438
8
MT RRR INITIATIVE
2,496,572
9
Ochrane Radial Gate Hoist Upgrad
2,488,629
10
Great Falls 230Kv - EASTSIDE
1,768,366
11
Johnson Lane Bank 1
1,715,623
12
Hauser U1 Turb-Gen Upgrade
1,693,925
13
ADMS Training Development
1,645,439
14
Holter U2 Generator Rewind
1,524,860
15
Ashgrove Transformer Upgrade
1,388,285
16
Bradley Creek 161Kv PCB
1,303,854
17
CROOKED FALLS-GREAT FALLS ES
1,149,101
18
Bozeman Three Rivers Bnk 1
1,135,523
19
Holter U2 Turbine Upgrade
1,129,066
20
Darby Bank 2 Replace
1,109,496
21
Billings Division Electric-Cap Blnkt Growth
1,051,440
22
Madison Spill Gates Screw Jacks
1,003,739
23
Minor Projects (Less than $1,000,000 - 285 items)
29,693,427
24
SOUTH DAKOTA
25
Hurton GT Bank 1
1,602,329
26
Minor Projects (Less than $1,000,000 - 183 items)
9,368,834
43
Total
314,784,647


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
ACCUMULATED PROVISION FOR DEPRECIATION OF ELECTRIC UTILITY PLANT (Account 108)
  1. Explain in a footnote any important adjustments during year.
  2. Explain in a footnote any difference between the amount for book cost of plant retired, Line 12, column (c), and that reported for electric plant in service, page 204, column (d), excluding retirements of non-depreciable property.
  3. The provisions of Account 108 in the Uniform System of Accounts require that retirements of depreciable plant be recorded when such plant is removed from service. If the respondent has a significant amount of plant retired at year end which has not been recorded and/or classified to the various reserve functional classifications, make preliminary closing entries to tentatively functionalize the book cost of the plant retired. In addition, include all costs included in retirement work in progress at year end in the appropriate functional classifications.
  4. Show separately interest credits under a sinking fund or similar method of depreciation accounting.
Line No.
Item
(a)
Total (c + d + e)
(b)
Electric Plant in Service
(c)
Electric Plant Held for Future Use
(d)
Electric Plant Leased To Others
(e)
Section A. Balances and Changes During Year
1
AccumulatedProvisionForDepreciationOfElectricUtilityPlant
Balance Beginning of Year
(a)
1,950,712,066
1,950,712,066
2
Depreciation Provisions for Year, Charged to
3
DepreciationExpenseExcludingAdjustments
(403) Depreciation Expense
143,537,392
143,537,392
4
DepreciationExpenseForAssetRetirementCosts
(403.1) Depreciation Expense for Asset Retirement Costs
5
ExpensesOfElectricPlantLeasedToOthers
(413) Exp. of Elec. Plt. Leas. to Others
6
TransportationExpensesClearing
Transportation Expenses-Clearing
7
OtherClearingAccounts
Other Clearing Accounts
8
OtherAccounts
Other Accounts (Specify, details in footnote):
9.1
Other Accounts (Specify, details in footnote):
10
DepreciationProvision
TOTAL Deprec. Prov for Year (Enter Total of lines 3 thru 9)
143,537,392
143,537,392
11
Net Charges for Plant Retired:
12
BookCostOfRetiredPlant
Book Cost of Plant Retired
91,599,411
91,599,411
13
CostOfRemovalOfPlant
Cost of Removal
14,338,154
14,338,154
14
SalvageValueOfRetiredPlant
Salvage (Credit)
1,725,809
1,725,809
15
NetChargesForRetiredPlant
TOTAL Net Chrgs. for Plant Ret. (Enter Total of lines 12 thru 14)
104,211,756
104,211,756
16
OtherAdjustmentsToAccumulatedDepreciation
Other Debit or Cr. Items (Describe, details in footnote):
17.1
Other Debit or Cr. Items (Describe, details in footnote):
17,772
17,772
17.2
Transfers
960
960
18
BookCostOfAssetRetirementCosts
Book Cost or Asset Retirement Costs Retired
19
AccumulatedProvisionForDepreciationOfElectricUtilityPlant
Balance End of Year (Enter Totals of lines 1, 10, 15, 16, and 18)
1,990,020,890
1,990,020,890
Section B. Balances at End of Year According to Functional Classification
20
AccumulatedDepreciationSteamProduction
Steam Production
151,989,438
151,989,438
21
AccumulatedDepreciationNuclearProduction
Nuclear Production
22
AccumulatedDepreciationHydraulicProductionConventional
Hydraulic Production-Conventional
139,268,540
139,268,540
23
AccumulatedDepreciationHydraulicProductionPumpedStorage
Hydraulic Production-Pumped Storage
24
AccumulatedDepreciationOtherProduction
Other Production
140,096,686
140,096,686
25
AccumulatedDepreciationTransmission
Transmission
504,039,369
504,039,369
26
AccumulatedDepreciationDistribution
Distribution
946,719,166
946,719,166
27
AccumulatedDepreciationRegionalTransmissionAndMarketOperation
Regional Transmission and Market Operation
28
AccumulatedDepreciationGeneral
General
107,907,691
107,907,691
29
AccumulatedProvisionForDepreciationOfElectricUtilityPlant
TOTAL (Enter Total of lines 20 thru 28)
1,990,020,890
1,990,020,890


FOOTNOTE DATA

(a) Concept: AccumulatedProvisionForDepreciationOfElectricUtilityPlant
Montana Operations
Section A. Balances and Changes During Year 2022 MONTANA DATA ONLY
Line
No.
Item Total (c+d+e) Electric Plant in
Service
(a) (b) (c)
1 Balance Beginning of Year 1,589,818,437  1,589,818,437 
2 Depreciation Provisions for Year, Charged to
3 (403) Depreciation Expense 111,425,479  111,425,479 
4 (403.1) Depreciation Expense for Asset Retirement Costs
5 (413) Exp. of Elec. Plt. Leas. to Others
6 Transportation Expenses-Clearing
7 Other Clearing Accounts
8 Other Accounts (Specify, details in footnote):
9
10 TOTAL Deprec. Prov for Year (Enter Total of lines 3 thru 9) 111,425,479  111,425,479 
11 Net Charges for Plant Retired:
12 Book Cost of Plant Retired 83,449,972  83,449,972 
13 Cost of Removal 12,843,020  12,843,020 
14 Salvage (Credit) 1,507,966  1,507,966 
15 TOTAL Net Chrgs. for Plant Ret. (Enter Total of lines 12 thru 14) 94,785,026  94,785,026 
16 Other Debit or Cr. Items (Describe, details in footnote): (17,773) (17,773)
17 Transfers 959  959 
18 Book Cost or Asset Retirement Costs Retired
19 Balance End of Year (Enter Totals of lines 1, 10, 15, 16, and 18) 1,606,442,076  1,606,442,076 
Section B. Balances at End of Year According to Functional Classification
20 Steam Production 30,892,927  30,892,927 
21 Nuclear Production —  — 
22 Hydraulic Production-Conventional 139,268,540  139,268,539 
23 Hydraulic Production-Pumped Storage —  — 
24 Other Production 78,783,912  78,783,911 
25 Transmission 418,967,210  418,967,210 
26 Distribution 841,220,309  841,220,309 
27 General 97,309,180  97,309,180 
28 TOTAL (Enter Total of lines 20 thru 27) 1,606,442,078  1,606,442,076 
South Dakota Operations
Section A. Balances and Changes During Year 2023 SOUTH DAKOTA DATA ONLY
Line
No.
Item Total (c+d+e) Electric Plant in
Service
(a) (b) (c)
1 Balance Beginning of Year 360,893,629  360,893,629 
2 Depreciation Provisions for Year, Charged to
3 (403) Depreciation Expense 32,111,914  32,111,914 
4 (403.1) Depreciation Expense for Asset Retirement Costs
5 (413) Exp. of Elec. Plt. Leas. to Others
6 Transportation Expenses-Clearing
7 Other Clearing Accounts
8 Other Accounts (Specify, details in footnote):
9
10 TOTAL Deprec. Prov for Year (Enter Total of lines 3 thru 9) 32,111,914  32,111,914 
11 Net Charges for Plant Retired:
12 Book Cost of Plant Retired 8,149,439  8,149,439 
13 Cost of Removal 1,495,135  1,495,135 
14 Salvage (Credit) 217,843  217,843 
15 TOTAL Net Chrgs. for Plant Ret. (Enter Total of lines 12 thru 14) 9,426,731  9,426,731 
16 Other Debit or Cr. Items (Describe, details in footnote): —  — 
17
18 Book Cost or Asset Retirement Costs Retired —  — 
19 Balance End of Year (Enter Totals of lines 1, 10, 15, 16, and 18) 383,578,812  383,578,812 
Section B. Balances at End of Year According to Functional Classification
20 Steam Production 121,096,511  121,096,511 
21 Nuclear Production —  — 
22 Hydraulic Production-Conventional —  — 
23 Hydraulic Production-Pumped Storage —  — 
24 Other Production 61,312,774  61,312,774 
25 Transmission 85,072,160  85,072,160 
26 Distribution 105,498,857  105,498,857 
27 General 10,598,510  10,598,510 
28 TOTAL (Enter Total of lines 20 thru 27) 383,578,812  383,578,812 
Section A. Balances and Changes During Year 2022 SOUTH DAKOTA DATA ONLY
Line
No.
Item Total (c+d+e) Electric Plant in
Service
(a) (b) (c)
1 Balance Beginning of Year 337,633,297  337,633,297 
2 Depreciation Provisions for Year, Charged to
3 (403) Depreciation Expense 30,076,718  30,076,718 
4 (403.1) Depreciation Expense for Asset Retirement Costs
5 (413) Exp. of Elec. Plt. Leas. to Others
6 Transportation Expenses-Clearing
7 Other Clearing Accounts
8 Other Accounts (Specify, details in footnote):
9
10 TOTAL Deprec. Prov for Year (Enter Total of lines 3 thru 9) 30,076,718  30,076,718 
11 Net Charges for Plant Retired:
12 Book Cost of Plant Retired 5,703,075  5,703,075 
13 Cost of Removal 1,625,787  1,625,787 
14 Salvage (Credit) 516,823  516,823 
15 TOTAL Net Chrgs. for Plant Ret. (Enter Total of lines 12 thru 14) 6,812,039  6,812,039 
16 Other Debit or Cr. Items (Describe, details in footnote): -4,347  -4,347 
17
18 Book Cost or Asset Retirement Costs Retired —  — 
19 Balance End of Year (Enter Totals of lines 1, 10, 15, 16, and 18) 360,893,629  360,893,629 
Section B. Balances at End of Year According to Functional Classification
20 Steam Production 117,685,776  117,685,776 
21 Nuclear Production —  — 
22 Hydraulic Production-Conventional —  — 
23 Hydraulic Production-Pumped Storage —  — 
24 Other Production 55,268,911  55,268,911 
25 Transmission 78,877,311  78,877,311 
26 Distribution 98,729,128  98,729,128 
27 General 10,332,503  10,332,503 
28 TOTAL (Enter Total of lines 20 thru 27) 360,893,629  360,893,629 

Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
INVESTMENTS IN SUBSIDIARY COMPANIES (Account 123.1)
  1. Report below investments in Account 123.1, Investments in Subsidiary Companies.
  2. Provide a subheading for each company and list thereunder the information called for below. Sub-TOTAL by company and give a TOTAL in columns (e), (f), (g) and (h). (a) Investment in Securities - List and describe each security owned. For bonds give also principal amount, date of issue, maturity, and interest rate. (b) Investment Advances - Report separately the amounts of loans or investment advances which are subject to repayment, but which are not subject to current settlement. With respect to each advance show whether the advance is a note or open account. List each note giving date of issuance, maturity date, and specifying whether note is a renewal.
  3. Report separately the equity in undistributed subsidiary earnings since acquisition. The TOTAL in column (e) should equal the amount entered for Account 418.1.
  4. For any securities, notes, or accounts that were pledged designate such securities, notes, or accounts in a footnote, and state the name of pledgee and purpose of the pledge.
  5. If Commission approval was required for any advance made or security acquired, designate such fact in a footnote and give name of Commission, date of authorization, and case or docket number.
  6. Report column (f) interest and dividend revenues from investments, including such revenues from securities disposed of during the year.
  7. In column (h) report for each investment disposed of during the year, the gain or loss represented by the difference between cost of the investment (or the other amount at which carried in the books of account if different from cost) and the selling price thereof, not including interest adjustment includible in column (f).
  8. Report on Line 42, column (a) the TOTAL cost of Account 123.1.
Line No.
DescriptionOfInvestmentsInSubsidiaryCompanies
Description of Investment
(a)
DateOfAcquisitionInvestmentsInSubsidiaryCompanies
Date Acquired
(b)
DateOfMaturityInvestmentsInSubsidiaryCompanies
Date of Maturity
(c)
InvestmentInSubsidiaryCompanies
Amount of Investment at Beginning of Year
(d)
EquityInEarningsOfSubsidiaryCompanies
Equity in Subsidiary Earnings of Year
(e)
InterestAndDividendRevenueFromInvestments
Revenues for Year
(f)
InvestmentInSubsidiaryCompanies
Amount of Investment at End of Year
(g)
InvestmentGainLossOnDisplosal
Gain or Loss from Investment Disposed of
(h)
1
NorthWestern Services, LLC
2
NorthWestern Services, LLC - Capital Stock
3
NorthWestern Services, LLC - Paid in Capital
1,803,694
1,803,694
4
NorthWestern Services, LLC - Equity in Undistributed Earnings
287,451
44,536
331,987
5
Risk Partners Assurance, Ltd.
6
Risk Partners Assurance, Ltd. - Capital Stock
1,520,000
1,520,000
7
Risk Partners Assurance, Ltd. - Equity in Undistributed Earnings
388,710
34,124
422,834
8
Canadian Montana Pipeline Corporation
02/15/2002
9
Canadian Montana Pipeline Corporation - Translation Adjustment
1,683,932
1,686,317
10
Canadian Montana Pipeline Corporation - Paid in Capital
1,388,429
1,388,429
11
Canadian Montana Pipeline Corporation - Equity in Undistributed Earnings
1,911,475
195,539
2,107,015
12
Havre Pipeline Company
12/01/2013
13
Havre Pipeline Company - Paid in Capital
13,376,259
16,626,690
14
Havre Pipeline Company - Equity in Undistributed Earnings
1,976,866
1,487,304
3,464,170
15
NorthWestern Energy Solutions
06/01/2018
16
NorthWestern Energy Solutions - Capital Stock
5,793,954
11,852,827
17
NorthWestern Energy Solutions - Equity in Undistributed Earnings
55,682
55,682
18
NorthWestern Public Service - Capital Stock
09/29/2023
1
42
Total Cost of Account 123.1 $
Total
25,343,937
1,281,354
33,374,273


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
MATERIALS AND SUPPLIES
  1. For Account 154, report the amount of plant materials and operating supplies under the primary functional classifications as indicated in column (a); estimates of amounts by function are acceptable. In column (d), designate the department or departments which use the class of material.
  2. Give an explanation of important inventory adjustments during the year (in a footnote) showing general classes of material and supplies and the various accounts (operating expenses, clearing accounts, plant, etc.) affected debited or credited. Show separately debit or credits to stores expense clearing, if applicable.
Line No.
Account
(a)
Balance Beginning of Year
(b)
Balance End of Year
(c)
Department or Departments which Use Material
(d)
1
Fuel Stock (Account 151)
7,724,941
9,710,818
Electric & Gas
2
Fuel Stock Expenses Undistributed (Account 152)
3
Residuals and Extracted Products (Account 153)
4
Plant Materials and Operating Supplies (Account 154)
5
Assigned to - Construction (Estimated)
67,595,939
80,236,296
Electric, Gas, & Common
6
Assigned to - Operations and Maintenance
7
Production Plant (Estimated)
733,334
804,673
Electric & Gas
8
Transmission Plant (Estimated)
767,707
1,269,432
Electric, Gas, & Common
9
Distribution Plant (Estimated)
2,057,268
2,944,092
Electric, Gas, & Common
10
Regional Transmission and Market Operation Plant (Estimated)
11
Assigned to - Other (provide details in footnote)
12
TOTAL Account 154 (Enter Total of lines 5 thru 11)
71,154,248
85,254,493
13
Merchandise (Account 155)
14
Other Materials and Supplies (Account 156)
15
Nuclear Materials Held for Sale (Account 157) (Not applic to Gas Util)
16
Stores Expense Undistributed (Account 163)
17
18
19
20
TOTAL Materials and Supplies
78,879,189
(a)(b)
94,965,311


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
FOOTNOTE DATA

(a) Concept: MaterialsAndOperatingSupplies
Montana Operations
Line
No.
Account

(a)
Gas


(b)
Electric
Transmission

(c )
Other Electric


(d)
Total


(e)
1 Fuel Stock (Account 151) 856,272  —  1,298,938  2,155,210 
2 Fuel Stock Expense Undistributed (Account 152) — 
3 Residuals and Extracted Products (Account 153)
4 Plant Materials and Operating Supplies (Account 154)
5 Assigned to - Construction (Estimated) 8,913,864  13,409,315  39,311,033  61,634,212 
6 Assigned to - Operations and Maintenance
7 Production Plant (Estimated) 1,607  —  524,803  526,410 
8 Transmission Plant (Estimated) 177,908  906,136  —  1,084,044 
9 Distribution Plant (Estimated) 422,841  —  2,131,646  2,554,487 
10 Regional Transmission and Market Operation Plant (Estimated)
11 Assigned to - Other
12 TOTAL Account 154 (Enter Total of lines 5 thru 10) 9,516,220  14,315,451  41,967,482  65,799,153 
13 Merchandise (Account 155)
14 Other Materials and Supplies (Account 156)
15 Nuclear Materials Held for Sale (Account 157)
16 Store Expense Undistributed (Account 163)
17
18
19
20 TOTAL Materials and Supplies (Per Balance Sheet) 10,372,492  14,315,451  43,266,420  67,954,363 
(b) Concept: MaterialsAndOperatingSupplies
Montana Operations
Line
No.
Account

(a)
Balance
Beginning of
Year
(b)
Balance
End of Year
(c )
Estimate of
Portion
Attributable to
Construction
Balance
End of Year
w/ Assigned
to
Construction
(c )
Department or
Departments which
Use Material
(d)
1 Fuel Stock (Account 151) 2,283,502  2,155,210  2,155,210  Electric & Gas
2 Fuel Stock Expense Undistributed (Account 152)
3 Residuals and Extracted Products (Account 153)
4 Plant Materials and Operating Supplies (Account 154)
5 Assigned to - Construction (Estimated) —  —  61,634,212  61,634,212  Electric, Gas, & Common
6 Assigned to - Operatons and Maintenance — 
7 Production Plant (Estimated) 7,399,061  8,316,399  (7,789,989) 526,410  Electric & Gas
8 Transmission Plant (Estimated) 11,304,264  17,126,102  (16,042,058) 1,084,044  Electric, Gas, & Common
9 Distribution Plant (Estimated) 34,590,716  40,356,652  (37,802,165) 2,554,487  Electric, Gas, & Common
10 Regional Transmission and Market Operation Plant (Estimated)
11 Assigned to - Other —  —  — 
12 TOTAL Account 154 (Enter Total of lines 5 thru 10) 53,294,041  65,799,153  —  65,799,153 
13 Merchandise (Account 155)
14 Other Materials and Supplies (Account 156)
15 Nuclear Materials Held for Sale (Account 157)
16 Store Expense Undistributed (Account 163) —  — 
17
18
19
20 TOTAL Materials and Supplies (Per Balance Sheet) 55,577,543  67,954,363  —  67,954,363 
South Dakota Operations
Line
No.
Account

(a)
Balance
Beginning of
Year
(b)
Balance
End of Year
(c )
Estimate of
Portion
Attributable to
Construction
Balance
End of Year w/ Assigned to
Construction

(c )
Department or
Departments which
Use Material
(d)
1 Fuel Stock (Account 151) 5,441,439  7,555,608  7,555,608  Electric & Gas
2 Fuel Stock Expense Undistributed (Account 152)
3 Residuals and Extracted Products (Account 153)
4 Plant Materials and Operating Supplies (Account 154)
5 Assigned to - Construction (Estimated) —  —  18,602,085  18,602,085  Electric & Gas
6 Assigned to - Operations and Maintenance
7 Production Plant (Estimated) 6,008,636  6,344,762  (6,066,499) 278,263  Electric & Gas
8 Transmission Plant (Estimated) 3,979,312  4,227,087  (4,041,698) 185,389  Electric & Gas
9 Distribution Plant (Estimated) 7,872,259  8,883,491  (8,493,888) 389,603  Electric & Gas
10 Regional Transmission and Market Operation Plant (Estimated)
11 Assigned to - Other —  —  —  Common
12 TOTAL Account 154 (Enter Total of lines 5 thru 10) 17,860,207  19,455,340  —  19,455,340 
13 Merchandise (Account 155)
14 Other Materials and Supplies (Account 156) Electric & Gas
15 Nuclear Materials Held for Sale (Account 157)
16 Store Expense Undistributed (Account 163) Electric & Gas
17
18
19
20 TOTAL Materials and Supplies (Per Balance Sheet) 23,301,646  27,010,948  —  27,010,948 

Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
Allowances (Accounts 158.1 and 158.2)
  1. Report below the particulars (details) called for concerning allowances.
  2. Report all acquisitions of allowances at cost.
  3. Report allowances in accordance with a weighted average cost allocation method and other accounting as prescribed by General Instruction No. 21 in the Uniform System of Accounts.
  4. Report the allowances transactions by the period they are first eligible for use: the current year’s allowances in columns (b)-(c), allowances for the three succeeding years in columns (d)-(i), starting with the following year, and allowances for the remaining succeeding years in columns (j)-(k).
  5. Report on Line 4 the Environmental Protection Agency (EPA) issued allowances. Report withheld portions Lines 36-40.
  6. Report on Line 5 allowances returned by the EPA. Report on Line 39 the EPA’s sales of the withheld allowances. Report on Lines 43-46 the net sales proceeds and gains/losses resulting from the EPA’s sale or auction of the withheld allowances.
  7. Report on Lines 8-14 the names of vendors/transferors of allowances acquired and identify associated companies (See "associated company" under "Definitions" in the Uniform System of Accounts).
  8. Report on Lines 22 - 27 the name of purchasers/ transferees of allowances disposed of and identify associated companies.
  9. Report the net costs and benefits of hedging transactions on a separate line under purchases/transfers and sales/transfers.
  10. Report on Lines 32-35 and 43-46 the net sales proceeds and gains or losses from allowance sales.
Current Year Year One Year Two Year Three Future Years Totals
Line No.
SO2 Allowances Inventory (Account 158.1)
(a)
No.
(b)
Amt.
(c)
No.
(d)
Amt.
(e)
No.
(f)
Amt.
(g)
No.
(h)
Amt.
(i)
No.
(j)
Amt.
(k)
No.
(l)
Amt.
(m)
1
Balance-Beginning of Year
4,106
4,106
4,106
4,106
42,992
59,416
2
3
Acquired During Year:
4
Issued (Less Withheld Allow)
5
Returned by EPA
6
7
8
Purchases/Transfers:
9
10
11
12
13
14
15
Total
16
17
Relinquished During Year:
18
Charges to Account 509
19
Other:
20
Allowances Used
20.1
Allowances Used
21
Cost of Sales/Transfers:
22
23
24
25
26
27
28
Total
29
Balance-End of Year
4,106
4,106
4,106
4,106
39,763
56,187
30
31
Sales:
32
Net Sales Proceeds(Assoc. Co.)
33
Net Sales Proceeds (Other)
34
Gains
35
Losses
Allowances Withheld (Acct 158.2)
36
Balance-Beginning of Year
37
Add: Withheld by EPA
38
Deduct: Returned by EPA
39
Cost of Sales
40
Balance-End of Year
41
42
Sales
43
Net Sales Proceeds (Assoc. Co.)
44
Net Sales Proceeds (Other)
45
Gains
46
Losses


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
Allowances (Accounts 158.1 and 158.2)
  1. Report below the particulars (details) called for concerning allowances.
  2. Report all acquisitions of allowances at cost.
  3. Report allowances in accordance with a weighted average cost allocation method and other accounting as prescribed by General Instruction No. 21 in the Uniform System of Accounts.
  4. Report the allowances transactions by the period they are first eligible for use: the current year’s allowances in columns (b)-(c), allowances for the three succeeding years in columns (d)-(i), starting with the following year, and allowances for the remaining succeeding years in columns (j)-(k).
  5. Report on Line 4 the Environmental Protection Agency (EPA) issued allowances. Report withheld portions Lines 36-40.
  6. Report on Line 5 allowances returned by the EPA. Report on Line 39 the EPA’s sales of the withheld allowances. Report on Lines 43-46 the net sales proceeds and gains/losses resulting from the EPA’s sale or auction of the withheld allowances.
  7. Report on Lines 8-14 the names of vendors/transferors of allowances acquired and identify associated companies (See "associated company" under "Definitions" in the Uniform System of Accounts).
  8. Report on Lines 22 - 27 the name of purchasers/ transferees of allowances disposed of and identify associated companies.
  9. Report the net costs and benefits of hedging transactions on a separate line under purchases/transfers and sales/transfers.
  10. Report on Lines 32-35 and 43-46 the net sales proceeds and gains or losses from allowance sales.
Current Year Year One Year Two Year Three Future Years Totals
Line No.
NOx Allowances Inventory (Account 158.1)
(a)
No.
(b)
Amt.
(c)
No.
(d)
Amt.
(e)
No.
(f)
Amt.
(g)
No.
(h)
Amt.
(i)
No.
(j)
Amt.
(k)
No.
(l)
Amt.
(m)
1
Balance-Beginning of Year
2
3
Acquired During Year:
4
Issued (Less Withheld Allow)
5
Returned by EPA
6
7
8
9
10
11
12
13
14
15
Total
16
17
Relinquished During Year:
18
Charges to Account 509
19
Other:
20
Allowances Used
20.1
Allowances Used
21
Cost of Sales/Transfers:
22
23
24
25
26
27
28
Total
29
Balance-End of Year
30
31
Sales:
32
Net Sales Proceeds(Assoc. Co.)
33
Net Sales Proceeds (Other)
34
Gains
35
Losses
Allowances Withheld (Acct 158.2)
36
Balance-Beginning of Year
37
Add: Withheld by EPA
38
Deduct: Returned by EPA
39
Cost of Sales
40
Balance-End of Year
41
42
Sales
43
Net Sales Proceeds (Assoc. Co.)
44
Net Sales Proceeds (Other)
45
Gains
46
Losses


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
EXTRAORDINARY PROPERTY LOSSES (Account 182.1)
WRITTEN OFF DURING YEAR
Line No.
DescriptionOfExtraordinaryPropertyLoss
Description of Extraordinary Loss [Include in the description the date of Commission Authorization to use Acc 182.1 and period of amortization (mo, yr to mo, yr).]
(a)
ExtraordinaryPropertyLossesNotYetRecognized
Total Amount of Loss
(b)
ExtraordinaryPropertyLossesRecognized
Losses Recognized During Year
(c)
ExtraordinaryPropertyLossesWrittenOffAccountCharged
Account Charged
(d)
ExtraordinaryPropertyLossesWrittenOff
Amount
(e)
ExtraordinaryPropertyLosses
Balance at End of Year
(f)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
20 TOTAL


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
UNRECOVERED PLANT AND REGULATORY STUDY COSTS (182.2)
WRITTEN OFF DURING YEAR
Line No.
DescriptionOfUnrecoveredPlantAndRegulatoryStudyCosts
Description of Unrecovered Plant and Regulatory Study Costs [Include in the description of costs, the date of COmmission Authorization to use Acc 182.2 and period of amortization (mo, yr to mo, yr)]
(a)
UnrecoveredPlantAndRegulatoryStudyCostsNotYetRecognized
Total Amount of Charges
(b)
UnrecoveredPlantAndRegulatoryStudyCostsRecognized
Costs Recognized During Year
(c)
UnrecoveredPlantAndRegulatoryStudyCostsWrittenOffAccountCharged
Account Charged
(d)
UnrecoveredPlantAndRegulatoryStudyCostsWrittenOff
Amount
(e)
UnrecoveredPlantAndRegulatoryStudyCosts
Balance at End of Year
(f)
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
TOTAL


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
Transmission Service and Generation Interconnection Study Costs
  1. Report the particulars (details) called for concerning the costs incurred and the reimbursements received for performing transmission service and generator interconnection studies.
  2. List each study separately.
  3. In column (a) provide the name of the study.
  4. In column (b) report the cost incurred to perform the study at the end of period.
  5. In column (c) report the account charged with the cost of the study.
  6. In column (d) report the amounts received for reimbursement of the study costs at end of period.
  7. In column (e) report the account credited with the reimbursement received for performing the study.
Line No.
DescriptionOfStudyPerformed
Description
(a)
StudyCostsIncurred
Costs Incurred During Period
(b)
StudyCostsAccountCharged
Account Charged
(c)
StudyCostsReimbursements
Reimbursements Received During the Period
(d)
StudyCostsAccountReimbursed
Account Credited With Reimbursement
(e)
1
Transmission Studies
2
FAC Studies
90,602
129,019
3
SIS Studies
230,479
299,617
4
Line Interconnection Studies
150,454
591,513
20
Total
471,535
1,020,149
21
Generation Studies
22
FAC Studies
519,052
2,243,519
23
SIS Studies
257,737
1,070,034
24
FEA Studies
271,179
558,654
25
Optional Studies
41,647
120,322
39
Total
1,089,615
3,992,529
40 Grand Total
1,561,150
5,012,678


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
OTHER REGULATORY ASSETS (Account 182.3)
  1. Report below the particulars (details) called for concerning other regulatory assets, including rate order docket number, if applicable.
  2. Minor items (5% of the Balance in Account 182.3 at end of period, or amounts less than $100,000 which ever is less), may be grouped by classes.
  3. For Regulatory Assets being amortized, show period of amortization.
CREDITS
Line No.
DescriptionAndPurposeOfOtherRegulatoryAssets
Description and Purpose of Other Regulatory Assets
(a)
OtherRegulatoryAssets
Balance at Beginning of Current Quarter/Year
(b)
IncreaseDecreaseInOtherRegulatoryAssets
Debits
(c)
OtherRegulatoryAssetsWrittenOffAccountCharged
Written off During Quarter/Year Account Charged
(d)
OtherRegulatoryAssetsWrittenOffRecovered
Written off During the Period Amount
(e)
OtherRegulatoryAssets
Balance at end of Current Quarter/Year
(f)
1
Flow-through Income Taxes (Montana)
444,386,121
39,563,304
483,949,425
2
Excess Deferred Income Taxes (Montana)
47,448,837
2,792,249
(a)
44,656,588
3
Basin Creek Capital Lease (Montana)
4,859,963
1,087,070
3,772,893
4
BPA Residential Exchange Program (Montana) - Docket 2018.8.49 Order 7630; Annual Amortization
1,193,372
4,658,761
4,681,087
1,171,046
5
Property Tax Tracker (Montana) - Docket 2017.11.86 - Order 7580a; Annual Amortization
11,432,710
24,349,283
35,781,993
6
FAS 106 (Montana) - Docket 93.6.24 and Docket 2009.9.129
10,658,733
257,460
4,061,074
6,855,119
7
FAS 112 (Montana) - Docket 93.6.24 and Docket 2009.9.129
5,879,275
2,192,241
3,687,034
8
Compensated Absences (Montana) - Docket 97.11.219
11,382,102
831,875
830,287
11,383,690
9
Pension Plan (Montana)
80,885,087
1,085,861
8,147,332
73,823,616
10
Montana Consumer Counsel Tax (Montana) - Docket 2018.10.67 - Order 7637
639,407
21,066
660,473
11
Montana Public Service Commission (Montana) - Docket 2017.9.78 - Order 7568
3,570,894
4,327,713
5,165,802
2,732,805
12
Natural Gas Transmission Verification Program (Montana) - Docket D2016.11.88
584,247
584,247
13
Montana Wildfire Mitigation
1,623,113
1,623,113
14
Asset Retirement Obligation (Montana)
15,421,503
2,385,569
17,807,072
15
Flow-through Income Taxes (South Dakota)
64,652,202
4,849,953
69,502,155
16
Excess Deferred Income Taxes (South Dakota)
6,915,405
167,880
6,747,525
17
Pension Plan (South Dakota)
7,079,702
1,265,007
(b)
5,814,695
18
Manufactured Gas Plants (South Dakota) - Docket NG 11-003
10,962,729
430,042
262,217
11,130,554
19
Field Inventory (South Dakota) - Docket EL 14-106
262,191
89,916
172,275
20
Asset Retirement Obligation (South Dakota)
869,896
135,429
1,005,325
21
Rate Case Costs (South Dakota) Docket EL 23-016
190,623
190,623
44
TOTAL
729,084,376
84,710,052
67,768,875
746,025,553


Name of Respondent:

NorthWestern Corporation
This report is:

(1)
An Original

(2)
A Resubmission
Date of Report:

12/31/2023
Year/Period of Report

End of:
2023
/
Q4
FOOTNOTE DATA

(a) Concept: OtherRegulatoryAssets
Line
No.
Description (a) (b) (c) (d)
MONTANA:
12/31/2022
Protected Unprotected
TCJA Excess ADIT Account Reduced 190 190 Subtotal