Snake River north of the dam.

Hells Canyon is a 10-mile-wide (16 km) canyon located along the border of eastern Oregon, eastern Washington and western Idaho in the United States. It is part of the Hells Canyon National Recreation Area and is North America's deepest river gorge at 7,993 feet (2,436 m).

The canyon was carved by the waters of the Snake River, which flows more than one mile (1.6 km) below the canyon's west rim on the Oregon side and 7,400 feet (2,300 m) below the peaks of Idaho's Seven Devils Mountains range to the east. Most of the area is inaccessible by road.