Hells Canyon is a ten mile wide canyon located along the border of eastern Oregon and western Idaho in the United States. It is North America's deepest river gorge at 7,993 feet (2436 m) and the most important feature of Hells Canyon National Recreation Area.
The canyon was carved by the waters of the Snake River and plunges more than a mile below the canyon's west rim on the Oregon side and 8,000 feet below the peaks of Idaho's Seven Devils Mountains range to the east. The area is inaccessible by road.
Aside from being known as the deepest river gorge in North America, the area offers scenic vistas of mountain peaks and cascading waters, and glimpses of abundant wildlife in a remote wilderness setting.
Prehistoric tribes roamed the area and artifacts from these earlier inhabitants as well as the colorful ruins of early miners and settlers are visible. The area can be experienced by land, trail or boat.
In 1806, three members of the Lewis and Clark Expedition entered Hells Canyon along the Salmon River. However, they turned back without seeing the canyon. It wasn't until 1811 that the Wilson Price 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, except their expedition journals.
The early miners were next to follow. In the 1860s gold was discovered in river bars near Hells Canyon National Recreation Area and miners soon penetrated Hells Canyon. Gold mining was not profitable here and evidence remains of their endeavors visible along the corridor of the Snake River. Later efforts concentrated on hard-rock mining requiring complex facilities, and evidence of the history of these developments are on view today, especially near the mouth of the Imnaha River. In the 1880s there was a short-lived homesteading boom but the weather was too severe for farming and they soon gave up. Some ranchers still remain today operating within the boundaries of the National Recreation Area.
The three dams are as follows: