The Frank Church-River of No Return is a wilderness of steep, rugged mountains, deep canyons, and wild, whitewater rivers. The Salmon River Mountains, located south of the Main Salmon and west of the Middle Fork, are the most massive range, and dominate the Wilderness. North of the Main Salmon River are the Clearwater Mountains, east of the Middle Fork are the Bighorn Crags. The Salmon River Canyon is one of the deepest gorges in North America, deeper even than the famous Grand Canyon of the Colorado in Arizona.