Snake River

Snake River
The Tetons and the Snake River (photographed by Ansel Adams, 1942) shows the Snake River in Jackson Hole, Wyoming.
Map of the Snake River watershed
Native name	Kimooenim (Nez Perce) Yampapah (Shoshoni)
Location
Country	United States
State	Wyoming, Idaho, Oregon, Washington
Region	Pacific Northwest
Cities	Jackson, Wyoming, Idaho Falls, Idaho, Blackfoot, Idaho, American Falls, Idaho, Burley, Idaho, Twin Falls, Idaho, Ontario, Oregon, Lewiston, Idaho, Clarkston, Washington, Tri-Cities, Washington
Physical characteristics
Source	Rocky Mountains
• location	Yellowstone National Park, Wyoming
• coordinates	44°07′49″N 110°13′10″W / 44.13028°N 110.21944°W / 44.13028; -110.21944[1]
• elevation	9,200 ft (2,800 m)[2]
Mouth	Columbia River at Lake Wallula
• location	Burbank, Washington, near the Tri-Cities
• coordinates	46°11′10″N 119°1′43″W / 46.18611°N 119.02861°W / 46.18611; -119.02861[1]
• elevation	341 ft (104 m)[1]
Length	1,080 mi (1,740 km)[3]
Basin size	107,500 sq mi (278,000 km2)[4]
Discharge
• location	Ice Harbor Dam, Washington, 9+1⁄2 miles (15.3 km) above the mouth, 1962–2023 average[5]
• average	49,580 cu ft/s (1,404 m3/s)[5]
• minimum	2,000 cu ft/s (57 m3/s)[5]
• maximum	305,000 cu ft/s (8,600 m3/s)[5]
Basin features
Tributaries
• left	Gros Ventre River, Salt River, Blackfoot River, Portneuf River, Bruneau River, Owyhee River, Malheur River, Burnt River, Powder River, Imnaha River, Grande Ronde River, Tucannon River[3]
• right	Henrys Fork, Malad River, Boise River, Payette River, Weiser River, Salmon River, Clearwater River, Palouse River[3]
National Wild and Scenic River
Type	Wild 260.8 miles (419.7 km) Scenic 186.4 miles (300.0 km) Recreational 33.8 miles (54.4 km)
Reference no.	P.L. 94-199; P.L. 111-11[6]

The Snake River is a major river in the interior Pacific Northwest region of the United States. About 1,080 miles (1,740 km) long, it is the largest tributary of the Columbia River, which is the largest North American river that empties into the Pacific Ocean. Beginning in Yellowstone National Park, western Wyoming, it flows across the arid Snake River Plain of southern Idaho, the rugged Hells Canyon on the borders of Idaho, Oregon and Washington, and finally the rolling Palouse Hills of southeast Washington. It joins the Columbia River just downstream from the Tri-Cities, Washington, in the southern Columbia Basin.

The river's watershed, which drains parts of six U.S. states, is situated between the Rocky Mountains to the north and east, the Great Basin to the south, and the Blue Mountains and Oregon high desert to the west. The region has a long history of volcanism; millions of years ago, Columbia River basalts covered vast areas of the western Snake River watershed, while the Snake River Plain was a product of the Yellowstone volcanic hotspot. The river was further altered by catastrophic flooding in the most recent Ice Age, which created such features as the Snake River Canyon and Shoshone Falls.

The Snake River once hosted some of the largest North American runs of salmon and other anadromous fish. For thousands of years, salmon fishing has played a central role in the culture and diet of indigenous peoples. The Shoshone and Nez Perce were the largest of several tribes that lived along the river by the turn of the 19th century. In 1805, while searching for a route from the eastern US to the Pacific, Lewis and Clark became the first non-natives to see the river. Fur trappers explored more of the watershed, and drove beaver to near extinction as the Americans and British vied for control of Oregon Territory.

Although travelers on the Oregon Trail initially shunned the dry and rocky Snake River region, a flood of settlers followed gold discoveries in the 1860s, leading to decades of military conflict and the eventual expulsion of tribes to reservations. At the turn of the 20th century, some of the first large irrigation projects in the western US were developed along the Snake River. South-central Idaho earned the nickname "Magic Valley" with the rapid transformation of desert into farmland. Numerous hydroelectric dams were also constructed, and four navigation dams on its lower section created a shipping channel to Lewiston, Idaho – the furthest inland seaport on the West Coast.

While dam construction, commercial fishing and other human activities have greatly reduced anadromous fish populations since the late 19th century, the Snake River watershed is still considered important habitat for these fish. The Snake and its tributary, the Salmon River, host the longest sockeye salmon run in the world, stretching 900 miles (1,400 km) from the Pacific to Redfish Lake, Idaho. Since the 1950s, public agencies, tribal governments and private utilities have invested heavily in fishery restoration and hatchery programs, with limited success. The proposed removal of the four lower Snake River dams for fish passage is a significant ongoing policy debate in the Pacific Northwest.