Hells Canyon Dam
Hells Canyon Dam is a concrete gravity dam in the western United States, on the Snake River  in Hells Canyon along the Idaho-Oregon border. At river mile 247, the dam impounds Hells Canyon Reservoir; its spillway elevation is 1,680 feet (512 m) above sea level. It is the third and final hydroelectric dam of the Hells Canyon Project, which includes Brownlee Dam (1959) and Oxbow Dam (1961), all built and operated by Idaho Power Company. The Hells Canyon Complex on the Snake River is the largest privately owned hydroelectric power complex in the nation, according to the US Energy Information Administration. The contractor for the Hells Canyon Dam was Morrison-Knudsen of Boise.