History of Hells Canyon

Hunt expedition explored Hells Canyon while seeking a shortcut to the Columbia River. Hunger and cold forced them to turn back, as did many explorers who were defeated by the canyon's inaccessibility. There remains no evidence in the canyon of their attempts; their expedition journals are the only documentation.

The early miners were next to follow. In the 1860s gold was discovered in river bars near present-day Hells Canyon National Recreation Area, and miners soon penetrated Hells Canyon. Gold mining was not profitable here. Evidence of their endeavors remains visible along the corridor of the Snake River. Later efforts concentrated on hard-rock mining, requiring complex facilities. Evidence of these developments is visible today, especially near the mouth of the Imnaha River.

In the 1880s there was a short-lived homesteading boom, but the weather was unsuited to farming and ranching, and most settlers soon gave up. However, some ranchers still operate within the boundaries of the National Recreation Area.

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, at river mile (RM) 285 or river kilometer (RK) 459, was finished in 1958. Oxbow Dam, 12 miles (19 km) downstream, was finished in 1961, and Hells Canyon Dam, 26 miles (42 km) below Oxbow, was completed in 1967. The three dams have a combined generating capacity of 1,167 megawatts (MW) of electricity. The complex, which provides about 70 percent of Idaho's hydroelectricity,