Snake River

Snake River
Lewis River, Shoshone River, Mad River, Saptin River, Yam-pah-pa, Lewis Fork
Adams The Tetons and the Snake River.jpg
The Tetons - Snake River (1942) by Ansel Adams
Snake River watershed map.png
Map of the Snake River watershed
CountryUnited States
StateWyoming, Idaho, Oregon, Washington
RegionPacific Northwest
CitiesJackson, WY, Idaho Falls, ID, Blackfoot, ID, American Falls, ID, Burley, ID, Twin Falls, ID, Ontario, OR, Lewiston, ID, Clarkston, WA, Tri-Cities, WA
Physical characteristics
SourceRocky Mountains
 ⁃ locationYellowstone National Park, Wyoming
 ⁃ coordinates44°7′49″N 110°13′10″W / 44°7′49″N 110°13′10″W / 44.13028; -110.21944[2]
 ⁃ elevation8,927 ft (2,721 m)[1]
MouthColumbia River at Lake Wallula
 ⁃ location
Franklin / Walla Walla counties, near Burbank, Washington[3]
 ⁃ coordinates
46°11′10″N 119°1′43″W / 46°11′10″N 119°1′43″W / 46.18611; -119.02861409,000 cu ft/s (11,600 m3/s)[7]
Basin features
 ⁃ leftHoback River, Salt River, Portneuf River, Bruneau River, Owyhee River, Malheur River, Burnt River, Powder River, Imnaha River, Grande Ronde River
 ⁃ rightHenrys Fork, Malad River, Boise River, Payette River, Weiser River, Salmon River, Clearwater River, Palouse River
TypeWild 268.4 miles (431.9 km)
Scenic 177.5 miles (285.7 km)
Recreational 33.8 miles (54.4 km)
Reference no.P.L. 94-199; P.L. 111-11

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, in turn the largest North American river that empties into the Pacific Ocean.[9] 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 River drainage basin encompasses parts of six U.S. states and is known for its varied geologic history. The Snake River Plain was created by a volcanic hotspot which now lies underneath the Snake River headwaters in Yellowstone National Park. Gigantic glacial-retreat flooding episodes that occurred during the previous Ice Age carved out canyons, cliffs and waterfalls along the middle and lower Snake River. Two of these catastrophic flooding events, the Missoula Floods and Bonneville Flood, significantly affected the river and its surroundings.

Prehistoric Native Americans lived along the Snake starting more than 11,000 years ago. Salmon from the Pacific Ocean spawned by the millions in the river, and were a vital resource for people living on the Snake downstream of Shoshone Falls. By the time Lewis and Clark explored the area, the Nez Perce and Shoshone were the dominant Native American groups in the region. Later explorers and fur trappers further changed and used the resources of the Snake River basin. At one point, sign language used by the Shoshones representing weaving baskets was misinterpreted to represent a snake, giving the Snake River its name.[10]

By the middle 19th century, the Oregon Trail had become well established, bringing numerous settlers to the Snake River region. Steamboats and railroads moved agricultural products and minerals along the river throughout the 19th and early 20th centuries. Starting in the 1890s, fifteen major dams have been built on the Snake River to generate hydroelectricity, enhance navigation, and provide irrigation water. 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.


The Snake River exits Jackson Lake and winds southwards through Jackson Hole

Formed by the confluence of three tiny streams on the southwest flank of Two Oceans Plateau in Yellowstone National Park, western Wyoming, the Snake starts out flowing west and south into Jackson Lake. Its first 50 miles (80 km) run through Jackson Hole, a wide valley between the Teton Range and the Gros Ventre Range. Below the tourist town of Jackson, the river turns west and flows through Snake River Canyon, cutting through the Snake River Range and into eastern Idaho. It receives the Hoback and Greys Rivers before entering Palisades Reservoir, where the Salt River joins at the mouth of Star Valley. Below Palisades Dam, the Snake River flows through the Snake River Plain, a vast arid physiographic province extending through southern Idaho southwest of the Rocky Mountains and underlain by the Snake River Aquifer, one of the most productive aquifers in the United States.[11][12][13][14][15]

Southwest of Rexburg, Idaho, the Snake is joined from the north by Henrys Fork. The Henrys Fork is sometimes called the North Fork of the Snake River, with the main Snake above their confluence known as the "South Fork". From there it turns south, flowing through downtown Idaho Falls, then past the Fort Hall Indian Reservation and into American Falls Reservoir, where it is joined by the Portneuf River. The Portneuf River Valley is an overflow channel that in the last glacial period carried floodwaters from pluvial Lake Bonneville into the Snake River, significantly altering the landscape of the Snake River Plain through massive erosion. From there the Snake resumes its journey west, entering the Snake River Canyon of Idaho. It is interrupted by several major cataracts, the largest being 212-foot (65 m) Shoshone Falls, which historically marked the upriver limit of migrating salmon.[11][16] A short distance downstream it passes under the Perrine Bridge.[12][17] Near Twin Falls, the Snake approaches the southernmost point in its entire course, after which it starts to flow west-northwest.[11][12][14][15]

The Clearwater River (left) joins the Snake River (center) at Lewiston

The Snake continues through its canyon, receiving the Malad River from the east near Bliss and then the Bruneau River from the south in C.J. Strike Reservoir. It passes through an agricultural valley about 30 miles (48 km) southwest of Boise and flows briefly west into Oregon, before turning north to define the Idaho–Oregon border. Here the Snake River almost doubles in size as it receives several major tributaries – the Owyhee from the southwest, then the Boise and Payette rivers from the east, and further downstream the Malheur River from the west and Weiser River from the east. North of Boise, the Snake enters Hells Canyon, a steep, spectacular, rapid-strewn gorge that cuts through the Salmon River Mountains and Blue Mountains of Idaho and Oregon. Hells Canyon is one of the most rugged and treacherous portions of the course of the Snake River, posing a major obstacle for 19th-century American explorers. Here the Snake is also impounded by Hells Canyon, Oxbow, and Brownlee Dams, which together make up the Hells Canyon Hydroelectric Project.[11][14][15][18]

At the halfway point in Hells Canyon, in one of the most remote and inaccessible sections of its course, the Snake River is joined from the east by its largest tributary, the Salmon River. From there, the Snake begins to form the Washington–Idaho border, receiving the Grande Ronde River from the west before receiving the Clearwater River from the east at Lewiston, which marks the head of navigation on the Snake. The river leaves Hells Canyon and turns west, winding through the Palouse Hills of eastern Washington. The Lower Snake River Project's four dams and navigation locks have transformed this part of the Snake River into a series of reservoirs. The confluence of the Snake and Columbia rivers at Burbank, Washington is part of Lake Wallula, the reservoir of McNary Dam. The Columbia River flows about 325 miles (523 km) further west to the Pacific Ocean near Astoria, Oregon.[11][14][15]

Other Languages
Afrikaans: Snakerivier
تۆرکجه: اسنیک چایی
беларуская: Снейк
български: Снейк Ривър
brezhoneg: Snake River
català: Riu Snake
čeština: Snake (řeka)
Deutsch: Snake River
español: Río Snake
Esperanto: Serpenta Rivero
euskara: Snake ibaia
فارسی: رود اسنیک
français: Snake (rivière)
한국어: 스네이크강
hrvatski: Snake (rijeka)
italiano: Snake (fiume)
қазақша: Снейк өзені
Kiswahili: Mto Snake
Kreyòl ayisyen: Snake (rivyè)
kurdî: Snake River
lietuvių: Gyvačių upė
Nederlands: Snake (rivier)
日本語: スネーク川
português: Rio Snake
română: Râul Snake
русский: Снейк
Simple English: Snake River
slovenščina: Snake River
српски / srpski: Снејк (река)
srpskohrvatski / српскохрватски: Snake (rijeka)
svenska: Snake River
українська: Снейк
Tiếng Việt: Sông Snake
中文: 斯内克河