Records (circa 1880-1947) of Montana Power Company predecessor companies consist of correspondence, financial records, legal documents, and minutes of many electric power, light, water, street railway, townsite, realty, and land companies around Western and Central Montana.

These U.S. Federal Power Commission records consist of hearing materials in a case involving the failure of the Montana Power Company to apply for a license to operate its hydroelectric dams on the Missouri River and tributaries. Exhibits in the case (including steamboat logs, diaries, articles, clippings, etc.) sought to document whether the Missouri River was navigable above Fort Benton. [FPC Docket #IT-5840.]