Controversy

 After completion of large hydropower dams on the Columbia River in the 1930s through the 1950s,
several entities sought approval from the Federal Power Commission to build dams on the Snake River, including a high dam in Hells Canyon. In 1955, the commission issued a license to the Idaho Power
Company to build a three-dam complex in the canyon. The first of the three, Brownlee Dam, was finished in 1958. Oxbow Dam, 12 miles downstream Brownlee Dam, was finished in 1961. Hells Canyon Dam, 26 miles below Oxbow, was completed in 1967. The complex, which provides about 70 percent of Idaho's hydroelectricity, blocks migration of salmon and other anadromous fish upstream of Hells Canyon Dam.