The Thompson Falls Hydroelectric Project (FERC No. 1869) has been in operation since 1915 and is located on the lower Clark Fork River near the town of Thompson Falls, Montana. In 2008, the licensee of the Project proposed the construction of an Upstream Fish Passage Facility at the dam to provide safe passage and improve habitat connectivity for native fishes and trout, specifically, the federally protected bull trout (Salvelinus confluentus), to their native upstream spawning waters.
In 2009, the Federal Energy Regulatory Commission (FERC) and U.S. Fish and Wildlife Service approved construction of a permanent upstream fish passage facility (fish ladder), at the project. Construction was completed in 2010, and the fish ladder commenced operations in 2011. The fish ladder operates annually between March and October and provides passage for native fishes, including bull trout, as well as several other salmonid and non-salmonid species.
The fish ladder was entirely funded by the licensee as part of its ongoing commitments to fisheries and river resources, as well as compliance with the Endangered Species Act.