Columbia River Basalt Group
- Salmon River (Idaho) (Wikipedia)
The Salmon River, also known as the “River of No Return”, is a river located in the U.S. state of Idaho in the western United States. It flows for 425 miles (685 km) through central Idaho, draining a rugged, thinly populated watershed of 14,000 square miles (36,000 km2). The river drops more than 7,000 feet (2,100 m) from its headwaters, near Galena Summit above the Sawtooth Valley in the Sawtooth National Recreation Area, to its confluence with the Snake River. Measured at White Bird, its average discharge is 11,060 cubic feet per second (82,700 US gal/s; 313 m3/s). The Salmon River is the longest undammed river in the contiguous United States.
Columbia River Basalt Group map shows main regions of basalt exposure in Washington, Oregon, Idaho and Nevada, USA. (usgs.gov)