The Snake River is a major river of the greater Pacific Northwest region in the United States. At 1,078 miles (1,735 km) long, it is the largest tributary of the Columbia River. It is also an important source of irrigation water for potatoes, sugar beets, and other crops. The Snake River rises in western Wyoming, then flows through the Snake River Plain of southern Idaho, the rugged Hells Canyon on the Oregon–Idaho border, and the rolling Palouse Hills of Washington, emptying into the Columbia River at the Tri-Cities, Washington.
The Snake is the largest tributary of the Columbia River. It has a mean discharge of 50,000 cubic feet per second (1,400 m³/s). According to the USGS, Snake is the 12th largest in the United States. Many dams have been built on the 1040 mile (1670 km) Snake River for providing irrigation water and hydroelectric power. The Snake River drainage basin encompasses parts of six U.S. states (Idaho, Washington, Oregon, Utah, Nevada, and Wyoming). It is known for its varied geologic history.
However, these dams blocked salmon migration above Hells Canyon and have led to water quality and environmental issues in certain parts of the river. The removal of several dams on the lower Snake River has been proposed, in order to restore some of the river’s once-tremendous salmon runs.