Snake River

This article is about the Snake River in the northwestern United States. For other uses, see Snake River (disambiguation)

The Snake River is a river in the western part of the United States. The Snake River is 1,038 miles (1,670 km) in length, and is the Columbia River's main tributary. The Lewis and Clark expedition (1803-6) was the first major U.S. exploration of the river.

Once known as the Lewis River, the Snake originates near the Continental Divide in Yellowstone National Park in NW Wyoming and flows south to Jackson Lake in Grand Teton National Park and past the city of Jackson. The river enters Idaho at the Palisades Reservoir and joins with the Henrys Fork River near Rigby. It then swings down in an arc across southern Idaho, forming the Snake River Plain. In doing so it passes through the city of Idaho Falls and the American Falls Reservor and then past Twin Falls and Boise to the Idaho/Oregon border. It then flows north through Hell's Canyon, and past the cities Lewiston, Idaho and Clarkston, Washington. It then flows into Washington, through many hydroelectric dams and finally joins the Columbia River near Pasco, Washington.

Tributaries of the Snake include the Henrys Fork River, the Boise River, the Salmon River, and the Clearwater River.

The Snake River's many hydroelectric power plants are a major source of electricity in the region. Its watershed provides irrigation for various projects, including the Minidoka, Boise, Palisades, and Owyhee projects by the U.S. Bureau of Reclamation, as well as a variety of private projects such as at Twin Falls.

The Snake runs through a number of gorges. The gorges include one of the deepest in the world, Hell's Canyon, with a maximum depth of 7,900 feet (2,410 m).

The name "Snake" possibly derived from an S-shaped (snake) sign which the Shoshone Indians made with their hands to mimic swimming salmon. The uppermost part of the river, from the point where Henrys Fork enters, is referred to informally as the South Fork Snake River. Variant Names:

Great Snake River
Lewis Fork
Lewis River
Mad River
Saptin River
Shoshone River
Yam-pah-pa

Counties through which the Snake flows:

Source for some material: U.S. Geological Survey