Hells Canyon is a ten-mile-wide (16 km) canyon in the Western United States , located along the border of eastern Oregon , western Idaho , and a small section of eastern Washington . It is part of the Hells Canyon National Recreation Area which is also located in part of the Wallowa-Whitman National Forest . It is North America's deepest river gorge at 7,993 feet (2,436 m), running deeper than the Grand Canyon in Arizona .
139-578: The canyon was carved by the waters of the Snake River , which flows more than one mile (1.6 km) below the canyon's west rim on the Oregon side and 7,400 feet (2,300 m) below the peaks of Idaho's Seven Devils Mountains to the east. This area includes 214,000 acres (87,000 ha) of wilderness. Most of the area is inaccessible by road. The geologic history of the rocks of Hells Canyon began 300 million years ago with an arc of volcanoes that emerged from
278-593: A Shoshone war party attacked a wagon train in the Boise Valley, and the U.S. Army mounted a counterattack, the Winnas Expedition . The situation became so unstable that Fort Boise was abandoned, and the Army had to escort wagon trains through the area. While early settlers had simply passed through this area on their way to Oregon, gold strikes brought renewed interest in the 1860s. The Army rebuilt Fort Boise further east of
417-463: 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
556-824: A forage fish of the smelt family found in the Atlantic and Arctic oceans. In summer, they graze on dense swarms of plankton at the edge of the ice shelf. Larger capelin also eat krill and other crustaceans . The capelin move inshore in large schools to spawn and migrate in spring and summer to feed in plankton rich areas between Iceland , Greenland and Jan Mayen . The migration is affected by ocean currents . Around Iceland maturing capelin make large northward feeding migrations in spring and summer. The return migration takes place in September to November. The spawning migration starts north of Iceland in December or January. The diagram on
695-580: A high degree of homing and the fish may make upstream or downstream migrations to reach very specific spawning locations in whitewater canyons. Sometimes fish can be dispersed by birds that eat fish eggs. They carry eggs in the digestive tracts and then deposit them in their faeces in a new place. The survival rate for fish eggs that have passed through a bird's digestive tract is low. Since prehistoric times humans have exploited certain anadromous fishes during their migrations into freshwater streams, when they are more vulnerable to capture. Societies dating to
834-518: A large network of canals and pump stations. The Minidoka Project would eventually bring water to a million acres (2,500 km ) of the Magic Valley. During World War II, many Japanese Americans interned at Minidoka were made to work on the project. The Boise Project , which would ultimately water 500,000 acres (200,000 ha) in and around the Boise Valley, was another major early reclamation undertaking. At its completion, Arrowrock Dam (1915) on
973-541: A license to the Idaho Power Company to build a three-dam complex in the canyon: The three dams have a combined generating capacity of 1,167 megawatts (MW) of electricity. The complex, which provides about 70 percent of Idaho's hydroelectricity , blocks migration of salmon and other anadromous fish upstream of Hells Canyon Dam. Two additional dams, Mountain Sheep and Pleasant Valley, were proposed in 1955 above
1112-653: A natural glacial lake enlarged by Jackson Lake Dam . It flows south through the alpine valley of Jackson Hole , which is situated between the Teton Range (to the west) and the Gros Ventre Range . Below the town of Jackson it forms the Snake River Canyon of Wyoming , turns west and crosses into Idaho , where the Palisades Dam forms Palisades Reservoir . From there it flows northwest through Swan Valley to join
1251-559: A rapid, forcing their retreat. On the Snake River above Hells Canyon, several steamboats were built at great expense (as manufactured parts such as engines had to be hauled in overland), the first being the Shoshone in 1866. However, running the upper Snake proved unprofitable, due to lack of demand. The owners of Shoshone decided to move her to the lower Snake River, and in April 1870, they made
1390-567: A series of massive flood basalt events that engulfed the Columbia Basin and surrounding lands, reshaped the landscape and erased most evidence of the pre-volcanic river channels starting about 17 Ma. Erupting from fissures in the southern Columbia Basin, the first basalt flows pushed the ancient Salmon-Clearwater much further north than its present course. About 12–10 Ma, the Blue Mountains region began to experience uplift, raising
1529-478: A steep grade, was connected three years later. In addition to commerce, the railroad also opened the Snake River region – which just a few years ago had been seen as a remote, rough frontier – to recreation. The Union Pacific heavily promoted tourism in places like Shoshone Falls, Payette Lake and Soda Springs, Idaho . Countering the reputation of southern Idaho as a wasteland, a brochure described Shoshone Falls: "Shoshone differs from every other waterfall in this or
SECTION 10
#17328443703681668-513: A third of the discharge at the mouth. Just two downstream tributaries, the Clearwater and Salmon Rivers, contribute about half of the total flow of the Snake. The 107,500-square-mile (278,000 km ) Snake River watershed drains about 87 percent of the state of Idaho, 18 percent of Washington and 17 percent of Oregon, in addition to small portions of Wyoming, Utah and Nevada . From
1807-730: Is 212-foot (65 m) Shoshone Falls , which in the spring flows with such force that 19th-century writers called it the "Niagara of the West". The Snake River continues flowing west, through the C. J. Strike Reservoir where it is joined from the left by the Bruneau River , then through the Morley Nelson Snake River Birds of Prey National Conservation Area before entering farmland on the western side of Idaho's Treasure Valley . Passing 30 miles (48 km) west of Boise , it crosses briefly into Oregon before turning north to form
1946-699: Is joined from the right by the Clearwater River , its largest tributary by volume. The Snake then turns sharply west to enter Washington. The final stretch of the Snake River flows through steep-sided valleys in the Palouse Hills of southeast Washington. Near Lyons Ferry State Park , it is joined from the left by the Tucannon River , then from the right by the Palouse River , which forms Palouse Falls about 8 miles (13 km) upstream of its confluence with
2085-843: Is primarily sagebrush , mixed with wheatgrasses and bunchgrasses . About 30 percent of the watershed is farmland; irrigated farming of potatoes, sugar beets, onions, cereal grains and alfalfa are dominant in the Snake River Plain, while the Palouse Hills of the northwest host mainly dryland wheat and legume production. About 15 percent of the watershed is forested, distributed across two temperate coniferous forest ecoregions : South Central Rockies forests , consisting primarily of Douglas fir , Engelmann spruce , subalpine fir , and lodgepole pine , and North Central Rockies forests , which include mountain hemlock , white spruce , alpine fir and western larch . About 4 percent of
2224-587: 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
2363-520: Is too rough for most cars, reaches the river at Dug Bar, 21 miles (34 km) from Imnaha, Oregon . On the canyon rims, viewpoints accessible by road include Hat Point and Buckhorn in Oregon and Heavens Gate in Idaho. Download coordinates as: Snake River 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
2502-771: The American eel and the European eel which migrate huge distances from freshwater rivers to spawn in the Sargasso Sea , and whose subsequent larvae can drift in currents for months and even years before returning to their natal rivers and streams as glass eels or elvers. An example of a euryhaline species is the bull shark , which lives in Lake Nicaragua of Central America and the Zambezi River of Africa. Both these habitats are fresh water, yet bull sharks will also migrate to and from
2641-782: The Bitterroot Range along the Idaho–Montana border. The Blue Mountains form much of the western boundary of the Snake watershed from southeast Washington down into Oregon. To the south are numerous small isolated mountain ranges of the Basin and Range Province , such as the Independence and Albion Mountains . To the east are more ranges of the Rockies including the Tetons and the Wind River Range ;
2780-513: The Blue Mountains of Oregon and Washington. The Hells Canyon Hydroelectric Complex includes the Brownlee , Oxbow and Hells Canyon Dams in the upper reaches of the canyon. Since its construction in 1967, Hells Canyon Dam has been the upriver limit for migrating salmon; in the past, salmon swam as far upriver as Shoshone Falls. Emerging from Hells Canyon Dam, the Snake surges northward through
2919-691: The Cayuse against the Shoshone, Bannock and Northern Paiute, and stopped the latter from expanding their territory towards the Columbia Plateau. Both the Nez Perce and Shoshone acquired horses in the late 1600s or early 1700s, enabling far-reaching trade and hunting expeditions. With horses, the Nez Perce were able to travel east of the Bitterroot Mountains to hunt bison, via the trail over Lolo Pass , which
SECTION 20
#17328443703683058-613: The Eastern Snake River Plain Aquifer . One of the largest groundwater reserves in the US, the aquifer is founded in porous volcanic rock underneath the plain. It absorbs and stores large volumes of water from the Snake River in the eastern Plain to re-emerge further west as springs in the Snake River Canyon. Water from the lost streams of Idaho , several rivers that disappear underground in the eastern Plain, travels through
3197-487: The Fort Hall Indian Reservation on the Snake River in southeast Idaho. Tribal resistance would continue for years to come. In 1877 the US government attempted to force the remaining Nez Perce onto their reservation, at which point Chief Joseph's band and several others opted to seek refuge elsewhere. After a treacherous crossing of the Snake at Dug Bar, Hells Canyon on May 31, the Nez Perce were pursued by
3336-509: The Hells Canyon Wilderness , where the majority of the river corridor is accessible only by boat and numerous Class III-IV rapids historically posed a major barrier to navigation. Today, the canyon and the surrounding Hells Canyon National Recreation Area are a popular location for whitewater boating, fishing, horseback riding and backpacking. With the adjacent Seven Devils Mountains rising up to 8,000 feet (2,400 m) above
3475-527: The Henrys Fork on an alluvial plain near Rexburg . The Henrys Fork is sometimes called the "North Fork" of the Snake River, while the section of the main Snake River above their confluence is sometimes called the "South Fork". Turning southwest, the river begins its long journey across the Snake River Plain, passing through Idaho Falls and receiving the Blackfoot River from the left before entering
3614-684: The Lost Trail Pass north of Salmon, Idaho to Tri-Basin Divide south of Afton, Wyoming , the eastern edge of the Snake River watershed follows the Continental Divide . As the Continental Divide also forms the Idaho–Montana border south of Lost Trail Pass, the Snake watershed touches Montana for a long distance, but does not extend into it. The Snake drains by far the largest area of any Columbia River tributary, making up about 40 percent of
3753-581: The Millingstone Horizon are known which exploited the anadromous fishery of Morro Creek and other Pacific coast estuaries . In Nevada the Paiute tribe has harvested migrating Lahontan cutthroat trout along the Truckee River since prehistoric times. This fishing practice continues to current times, and the U.S. Environmental Protection Agency has supported research to assure the water quality in
3892-632: The Montana Trail providing access to gold strikes in Montana Territory. This crossed the Snake River by the Eagle Rock Ferry and later a bridge which the city of Idaho Falls would soon grow around. As the flow of settlers increased, the Nez Perce and their neighbors the Cayuse and Walla Walla came under pressure to cede portions of their territory. Tensions flared in 1855 after tribes were coerced into relinquishing huge amounts of territory in
4031-760: The Nez Percé tribe . Others tribes visiting the area were the Shoshone-Bannock , northern Paiute and Cayuse Indians. The mild winters and ample plant and wildlife attracted human habitation. Pictographs and petroglyphs on the walls of the canyon are a record of the Indian settlements. In 1806, three members of the Lewis and Clark Expedition entered the Hells Canyon region along the Salmon River . They turned back without seeing
4170-508: The North West Company near the confluence of the Snake and Columbia Rivers. The following year, Mackenzie traveled up the Snake River and reached Boise Valley by making the first recorded river ascent of Hells Canyon. Mackenzie's goal was to bypass the arduous trek over the Blue Mountains. He wrote that "the passage by water is now proved to be safe and practicable for loaded boats, without one single carrying place or portage; therefore,
4309-810: The Sea of Cortez ) and the Yellowstone and upper Missouri Rivers (part of the Mississippi River system which drains to the Gulf of Mexico ). On the north it borders the watersheds of the Clark Fork and Spokane Rivers , both part of the Columbia River system. To the northwest it borders several other tributary watersheds of the Columbia River, including those of the John Day and Umatilla Rivers . Fifty-four named tributaries of
Hells Canyon - Misplaced Pages Continue
4448-564: The Treaty of Walla Walla . In retaliation for Lt. Col. Edward Steptoe 's defeat at the 1858 Battle of Pine Creek , a force led by Col. George Wright entered the lower Snake River country in 1859 and constructed Fort Taylor at the confluence of the Tucannon River below present-day Starbuck, Washington . Over several months Wright fought the natives along the river, killing their horses and destroying stored food. The sternwheeler Colonel Wright
4587-963: The United Nations Convention on the Law of the Sea (UNCLOS). The Convention does not provide an operational definition of the term, but in an annex (UNCLOS Annex 1) lists the species considered highly migratory by parties to the convention. The list includes: tuna and tuna-like species ( albacore , bluefin , bigeye tuna , skipjack , yellowfin , blackfin , little tunny , southern bluefin and bullet ), wahoo , pomfret , marlin , sailfish , swordfish , saury and oceangoing sharks , dolphins and other cetaceans . These high trophic level oceanodromous species undertake migrations of significant but variable distances across oceans for feeding, often on forage fish, or reproduction, and also have wide geographic distributions. Thus, these species are found both inside
4726-403: The exclusive economic zones of different nations, and these are covered differently in the treaty from other fish. Salmon and striped bass are well-known anadromous fish, and freshwater eels are catadromous fish that make large migrations. The bull shark is a euryhaline species that moves at will from fresh to salt water, and many marine fish make a diel vertical migration , rising to
4865-845: The high seas . Transboundary stock range in the EEZs of at least two countries. A stock can be both transboundary and straddling. It can be challenging to determine the population structure of highly migratory species using physical tagging. Traditional genetic markers such as short-range PCR products, microsatellites and SNP-arrays have struggled to identify population structure and distinguish fish stocks from separate ocean basins. However, population genomic research using RAD sequencing in yellowfin tuna, albacore, and wahoo has been able to distinguish populations from different ocean basins and reveal fine-scale population structure. Similar population genomics methods have also provided improved insight towards population structure in striped marlin . Some of
5004-515: The topography into a high plateau . The Snake River began carving Hells Canyon out of the plateau about 6 million years ago. Significant canyon-shaping events occurred as recently as 15,000 years ago during a massive outburst flood from Glacial Lake Bonneville in Utah. The canyon contains dense forests, scenic overlooks and mountain peaks. At the bottom of the canyon, the area is a dry, desert environment. The earliest known residents in Hells Canyon were
5143-483: The 1855 treaty. The US government sided with the settlers, and pressured some Nez Perce leaders into signing a second treaty which shrank their reservation by 90 percent. Many Nez Perce including Chief Joseph 's band refused to leave, calling the new treaty the "thief treaty". In March 1863, the Idaho Territory was split from Oregon, and Lewiston became its capital. More than 60,000 prospectors and others entered
5282-416: The 1860s, gold was discovered in river bars near present-day Hells Canyon National Recreation Area, and miners soon penetrated Hells Canyon; however, gold mining there was not profitable. Evidence of their endeavors remains visible along the corridor of the Snake River. Later efforts concentrated on hard-rock mining, requiring complex facilities. Evidence of these developments is visible today, especially near
5421-413: The 20-mile (32 km)-long American Falls Reservoir , formed by American Falls Dam . From American Falls it turns west, flowing through Minidoka Dam and Milner Dam , where large volumes of water are diverted for irrigation. Below Milner Dam it enters the Snake River Canyon of Idaho , where the river narrows, forming rapids and waterfalls. In the 70-mile (110 km) stretch between Milner Dam and
5560-444: The 200-nautical-mile (370-kilometre) exclusive economic zones and in the high seas outside these zones. They are pelagic species, which means they mostly live in the open ocean and do not live near the sea floor, although they may spend part of their life cycle in nearshore waters . Highly migratory species can be compared with straddling stock and transboundary stock . Straddling stock range both within an EEZ as well as in
5699-540: 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
Hells Canyon - Misplaced Pages Continue
5838-455: The Army for over 1,000 miles (1,600 km) east, through Yellowstone before turning north through Montana, fighting several battles along the way. On October 5, 1877, Chief Joseph surrendered to US forces. thus ending the Nez Perce War . The survivors were distributed to various reservations across the western US. In 1878, an uprising occurred in response to overcrowding and food shortages at
5977-477: The Blue Mountains to bypass Hells Canyon and reach the lower Snake River. After the hazardous experience, Hunt gave it the name "Mad River". A group led by Robert Stuart , a member of the Hunt expedition, returned eastward across the plain the following year. The route they mapped would eventually become that section of the Oregon Trail . In 1818 Donald Mackenzie and Alexander Ross established Fort Nez Percés for
6116-741: The Boise Project. Palisades Dam was built in 1956, providing flood control and irrigation for the Snake River above Idaho Falls, an area which the Bureau of Reclamation had previously overlooked. Near Rexburg, the Teton Dam was also built to provide water for this area. In 1976, the Teton Dam failed catastrophically, killing eleven people and causing at least $ 400 million in damage along the Henrys Fork and Snake Rivers. The political fallout from this disaster marked
6255-435: The Boise River was the tallest dam in the world, and its construction process was an important prototype for future federal projects such as Hoover Dam . Starting around the 1950s, farmers made heavy use of the Snake River aquifer, bringing large new areas into production. Surface water development also increased with projects such as Cascade Dam (1948) and Anderson Ranch Dam (1950), which provided additional storage for
6394-432: The Boise Valley, and a new city quickly grew around the U.S. Army post at Fort Boise. With Hells Canyon impractical for river navigation, interest grew in connecting the area by rail. By 1884, the Oregon Railroad & Navigation Company (later integrated into Union Pacific ) had connected Portland, Oregon , to the Union Pacific line at Granger, Wyoming , via Huntington and Pocatello . Boise, initially bypassed due to
6533-432: The Carey Act were in Idaho, and almost all of that utilized Snake River water. I. B. Perrine , who homesteaded near Shoshone Falls in the 1880s, went on to develop one of the most successful Carey Act projects. In 1900 Perrine filed a claim for water from the Snake River, and backed by significant private capital, oversaw the construction of Milner Dam and a canal system to irrigate some 250,000 acres (100,000 ha) of
6672-428: The Columbia Basin about 10.5 Ma, the Elephant Mountain basalt eruption forced the Salmon-Clearwater River into roughly its present course through southeast Washington. By 8.5 Ma the Salmon-Clearwater was established in the Columbia River's modern path through Wallula Gap , although the Columbia itself still flowed somewhere to the west. The last of the Columbia basalt flows occurred around 6 Ma; by then,
6811-447: 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
6950-500: The Fort Hall Reservation, leading to the Bannock War . The US army defeated the Bannock and their Paiute allies and proceeded to restrict travel in and out of the reservation. While Lewiston was now well connected by river, travel to Boise and other points upstream on the Snake River remained difficult due to the formidable obstacle of Hells Canyon. In 1865, Thomas Stump attempted to pilot the Colonel Wright up Hells Canyon, making it 80 miles (130 km) upriver before hitting rocks in
7089-408: The Idaho side of the river 22 miles (35 km) downstream to the Hells Canyon Dam. The road crosses the dam and continues another mile to the Hells Canyon Visitor Center on the Oregon side. Farther north on the Idaho side, Deer Creek Road connects White Bird, Idaho , to the river at Pittsburg Landing . Near the northern end of the canyon, Forest Road 4260 (Lower Imnaha Road), the last part of which
SECTION 50
#17328443703687228-409: The Lewis and Clark expedition would later follow in order to reach the Snake and Columbia Rivers. The river's modern name comes from a misunderstanding of the Shoshone Tribal Sign in PISL . The Plains Indians referred to the Shoshone people as "Snake People", while the Shoshone are believed to have referred to themselves as "People of the River of Many Fish". However, the Shoshone sign for "salmon"
7367-483: The Lewiston Valley by 1863. Many new steamboats were pressed into service, including the Spray , Cascadilla , Tenino , Okanogan , and Nez Perce Chief . The river's rapids posed a major navigation hazard, and from November to April the river was generally too low for ships. Despite these challenges, the water transport of freight and passengers was greatly profitable. Up river, the Shoshone and other tribes were also becoming increasingly wary of settlers; in 1854
7506-407: The Nez Perces, who they visited again on their return trip in 1806. Other explorers quickly followed, many of them fur trappers who began scouting the upper Snake River watershed for beaver. John Colter , a former member of the Lewis and Clark expedition, explored the Jackson Hole area in 1808. In 1810, Andrew Henry explored and named the Henrys Fork of the Snake River. He established Fort Henry,
7645-412: The Oregon Trail reached the Snake River at Fort Hall, Idaho , and stayed south of the river until Three Island Crossing near modern-day Glenns Ferry . Here the trail diverged, with the northern route fording the river to reach the HBC trading post at Fort Boise while the southern route continued into what is now the eastern Oregon desert. While the northern route passed through more favorable country,
7784-403: The Oregon–Idaho border. It is joined by several major tributaries in quick succession – the Boise River from the right, the Owyhee and Malheur Rivers from the left, the Payette and Weiser Rivers from the right near Ontario, Oregon , then the Powder and Burnt Rivers from the left. Continuing north, the river enters Hells Canyon , which slices between the Rocky Mountains of Idaho and
7923-414: The Salmon River at what is now Salmon, Idaho , naming the stream "Lewis's River". Thwarted by the river's rapids, they were forced to cross the Bitterroot Mountains via the Nez Perce trail at Lolo Pass. After paddling down the Kooskooskee (Clearwater River), they reached the junction with the Snake and camped there with the Nez Perces on October 10, 1805. They correctly surmised that the river coming from
8062-428: The Snake River Plain and the Palouse, though the majority of the Snake River Plain is Bureau of Land Management land. The Snake River watershed borders several other major North American watersheds. To the south it borders the endorheic Great Basin , including the area draining to Utah's Great Salt Lake . To the east it borders the watersheds of the Green River (part of the Colorado River system which drains to
8201-416: The Snake River Plain between 600 and 1500 CE. By the time of first European contact, the Snake River watershed was populated by several Native American tribes. The territory of the Nez Perce (Nimiipuu) stretched across what is now north-central Idaho, southeast Washington and northeast Oregon, including much of the lower Snake River below Hells Canyon, most of the Clearwater and Grande Ronde River, and
8340-401: The Snake River Plain formed as the North American Plate moved westward over the Yellowstone hotspot. Upwelling magma caused the continental crust to rise, forming highlands in a similar fashion to the modern Yellowstone plateau and leaving behind enormous basalt flows in its wake. As the hotspot migrated east relative to the North American Plate, the land behind it collapsed and sank, creating
8479-399: The Snake River Plain. Completed in 1905, the project was an immediate success. The rapid transformation of the barren landscape into productive farmland led to the moniker " Magic Valley ", and led to massive growth of the city of Twin Falls. During certain times of the year, almost all the Snake River's flow was diverted at Milner Dam, and since then, Shoshone Falls has regularly run dry in
SECTION 60
#17328443703688618-507: The Snake River at Ice Harbor Dam since 1962. The mean annual discharge for the 61-year period between 1962 and 2023 was 49,580 cubic feet per second (1,404 m /s), with a maximum recorded daily mean of 305,000 cu ft/s (8,600 m /s) on June 19, 1974, and a minimum daily mean of 2,000 cu ft/s (57 m /s) on November 29, 1961. A historic June 1894 flood at the Ice Harbor site reached an estimated peak of 409,000 cu ft/s (11,600 m /s). In terms of discharge,
8757-458: The Snake River drain more than 100 square miles (260 km ). Of these, the twelve listed below drain an area greater than 2,000 square miles (5,200 km ). The present-day course of the Snake River was pieced together over millions of years from several formerly disconnected drainage systems. Much of what would become the Pacific Northwest lay under shallow seas until it was uplifted starting about 60 million years ago (Ma). The outlet of
8896-427: The Snake River is the twelfth largest river in the United States, and it contributes about one-fifth of the Columbia's total outflow into the Pacific. The volume of the Snake River peaks in late spring and early summer as snow melts in the Rocky Mountains, and reaches its lowest point in the fall. Despite the numerous dams regulating its flow, its discharge into the Columbia remains highly seasonal. At Ice Harbor Dam,
9035-411: The Snake River posed a formidable barrier; during high water, many travelers were forced to take the hot, dry southern route, or risk drowning. Travelers going via Fort Boise had to cross the river one more time to rejoin the trail heading west. A ferry existed at Fort Boise since at least 1843; the Three Island crossing was also replaced by a ferry in 1869. A new wave of travelers came in the 1860s with
9174-477: The Snake River took several thousand salmon in one afternoon by means of spears." To the east and upriver of the falls, many Shoshone and Bannock lived in more nomadic groups, traveling to the falls during the spring salmon run then gathering camas bulbs and hunting bison through the summer and autumn months. The Snake River at Hells Canyon formed a natural dividing line between the Nez Perce and Shoshone, who considered each other enemies. The Nez Perce allied with
9313-607: The Snake River watershed derives from snowmelt. Jackson Hole, Wyoming experiences an alpine climate with an average of 30 in (760 mm) of rain and 252 in (6,400 mm) of snow. The coldest month is January, with a mean temperature of 13 °F (−11 °C), and the hottest is July at 57.7 °F (14.3 °C). Twin Falls experiences a semi-arid climate , with about 9 in (230 mm) of rain and 13 in (330 mm) of snow. Monthly mean temperatures range from 29.4 °F (−1.4 °C) in January to 73.1 °F (22.8 °C) in July. The Columbia Basin around
9452-449: 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
9591-430: The Snake empties into the Columbia River at Burbank, Washington , southeast of the Tri-Cities . The confluence is located on Lake Wallula , the impoundment behind McNary Dam on the Columbia, 341 feet (104 m) above sea level. From there, the Columbia River flows another 325 miles (523 km) west to empty into the Pacific Ocean. The U.S. Army Corps of Engineers has measured the discharge , or flow rate, of
9730-440: The Snake headwaters was sculpted by multiple Ice Age glaciations. Starting about 200,000 years ago, the Buffalo glaciation filled Jackson Hole to a depth of 2,000 feet (610 m). Ice flowed down the Snake River Canyon all the way to Idaho. The Bull Lake glaciation, about 80,000–35,000 years ago, and the Pinedale glaciation, ending about 15,000 years ago, were much smaller and did not fill the entire valley. These glaciations carved
9869-586: The Snake, Clearwater and Salmon Rivers. Clans gathered at communal fishing sites starting about May or June. Fishing moved from the lower rivers to higher elevation streams throughout the summer, while fall-run fish were preserved for winter use. Shoshones in the western part of the Snake River Plain also depended heavily on the salmon run. At Shoshone Falls and the smaller cataracts downstream, fishing platforms, temporary brush weirs, spears, baskets and fish traps were employed at large scale. Captain Benjamin Bonneville in 1832 observed that "Indians at Salmon Falls on
10008-449: The Snake. The Lower Snake River Project consists of four dams equipped with navigation locks – Lower Granite , Little Goose , Lower Monumental and Ice Harbor – which have transformed the once fast-flowing lower Snake River into a series of lakes, enabling heavy barges to travel between the Columbia River and the Port of Lewiston. About 10 miles (16 km) downstream from Ice Harbor Dam,
10147-587: The Tetons, and a graben valley developed between the Hoback and Teton fault zones, creating Jackson Hole. As the valley dropped, water filled it to create Lake Teewinot, which drained east into the Green River – Colorado River system. About 1 Ma, the Snake River captured the Jackson Hole watershed, draining Lake Teewinot and finally connecting the modern-day Snake headwaters to the rest of the river. This landscape around
10286-737: The Truckee can support suitable populations of the Lahontan cutthroat trout. Because salmonids live an anadromous lifestyle, they encounter a larger range of viruses from both freshwater and marine ecosystems. Myxovirus resistance (Mx) proteins are part of a GTP-ase family that aid in viral immunity, and previously, rainbow trout ( Oncorhynchus mykiss ) had been shown to possess three different Mx genes to aid in viral defence in both environments. The number of Mx genes can differ among species of fish, with numbers ranging from 1 to 9 and some outliers like Gadiformes that have totally lost their Mx genes. A study
10425-560: The ancestral Columbia River to the Pacific was established about 40 Ma. By about 17 Ma, the "Salmon-Clearwater River", or the modern day lower Snake River, flowed west into the Columbia and on to the Pacific. Another ancient river system drained what is now the western Snake River Plain. Some geologists propose that this flowed to the Columbia on a course south of the present-day Blue Mountains, while others propose it drained towards Northern California . The Columbia River basalts ,
10564-449: The aquifer to reach the Snake River, as does excess irrigation water absorbed into the ground. The major spring complexes at American Falls and Thousand Springs (near Hagerman, Idaho ) keep the river flowing steadily even in the driest of summers. At King Hill , about 50 miles (80 km) northwest of Twin Falls, water levels remain about 10,000 cu ft/s (280 m /s) for most of
10703-399: The availability of food in different areas at different times of year. The migratory movements may partly be linked to the fact that the fish cannot identify their own offspring and moving in this way prevents cannibalism . Some species have been described by the United Nations Convention on the Law of the Sea as highly migratory species. These are large pelagic fish that move in and out of
10842-417: The basalt layers to form a plateau. From about 11–9 Ma, crustal deformation related to the Yellowstone hotspot caused the western half of the Snake River Plain to sink, creating a graben -type valley between parallel fault zones to the northeast and southwest. The outlet of the ancient Snake River was blocked, and water accumulated to form the vast Lake Idaho starting about 10 Ma. The eastern half of
10981-552: The best-known anadromous fishes are the Pacific salmon species, such as Chinook (king), coho (silver), chum (dog), pink (humpback) and sockeye (red) salmon. These salmon hatch in small freshwater streams. From there they migrate to the sea to mature, living there for two to six years. When mature, the salmon return to the same streams where they were hatched to spawn. Salmon are capable of going hundreds of kilometers upriver, and humans must install fish ladders in dams to enable
11120-481: The building of dams. As with various other aspects of fish life, zoologists have developed empirical classifications for fish migrations. The first two following terms have been in long-standing wide usage, while others are of more recent coinage. George S. Myers coined the following terms in a 1949 journal article: Although these classifications originated for fish, they can apply, in principle, to any aquatic organism. List of diadromous orders and families, and
11259-452: The confluence with the Malad River near Hagerman Fossil Beds National Monument , the Snake River descends a total of 1,300 feet (400 m) over a series of cataracts and rapids, chief of which include Caldron Linn , Twin , Shoshone , Pillar , Auger, and Salmon Falls . Idaho Power operates several small hydroelectric plants along this stretch of the river. The largest single drop
11398-540: The creation of the Reclamation Service (now the Bureau of Reclamation ) in 1902, the federal government began to play a more direct role in water resources development. The expansive Minidoka Project was the first federal reclamation project in Idaho. Starting with Minidoka Dam in 1906, the project would grow over the next few decades to include major reservoirs at Jackson Lake , American Falls and Island Park , and
11537-575: The deep parts of the canyon. It was not until 1811 that the Wilson Price Hunt expedition explored Hells Canyon while seeking a shortcut to the Columbia River . Hunger and cold forced them to turn back, as also did many explorers who were defeated by the canyon's inaccessibility. There remains no evidence in the canyon of their attempts; their expedition journals are the only documentation. Early explorers sometimes called this area Box Canyon or Snake River Canyon. The early miners were next to follow. In
11676-441: The distinctive peaks of the Tetons into their present form and scoured lake basins in the valley floor, including modern-day Jackson Lake. While the Snake River course beyond Jackson Hole was not directly impacted by glaciations, its landscape was dramatically changed by Ice Age flooding events. About 30,000 years ago, the climate of western North America was much wetter than today. The Great Salt Lake Basin filled with water to form
11815-590: The doubtful question is set at rest forever. Yet from the force of the current and the frequency of rapids, it may still be advisable, and perhaps preferable, to continue the land transport." Canadian fur trappers with the British Hudson's Bay Company (HBC) reached the Snake River watershed in 1819. As American fur trappers kept coming to the region, the HBC ordered the Canadians to kill as many beavers as they could, under
11954-505: The easily farmable land was soon developed, and they could not raise the capital for further expansion. In addition, low water by late summer posed a challenge to farmers, and the irrigation companies could not afford to build dams to provide water storage. With many private irrigation companies verging on insolvency, the federal government began to explore programs assisting agricultural development. The 1894 Carey Act granted large tracts of dry federal land to western states, which then sold
12093-462: The end of large new irrigation developments not only for the Snake River system, but for the Bureau of Reclamation as a whole. Agriculture has significantly impacted water quality in the Snake River upstream of Hells Canyon. Water removed from the river for irrigation becomes contaminated with chemical fertilizers and manure, and percolates into the Snake River Aquifer. Pollutants collect in
12232-507: The entire Columbia River watershed. Compared with the Columbia above their confluence, the Snake River is about 180 miles (290 km) longer and drains a similarly sized area, though the Columbia carries more than twice the volume of water. The Snake River watershed is very mountainous, with the northern two-thirds of it occupied by vast mountain ranges of the Rockies, primarily the Salmon River Mountains of central Idaho and
12371-500: The first American fur trading post west of the Rocky Mountains, but abandoned it after that year's harsh winter. The 1811 Pacific Fur Company expedition led by Wilson Price Hunt attempted to find a route from Henrys Fork to the Columbia River. After suffering a wreck in the falls of the Snake River Canyon, they took an overland route through the Snake River Plain, through what is now the Boise Valley or Treasure Valley, then crossed
12510-474: The first successful river descent of Hells Canyon, a harrowing ride that skirted disaster several times. In 1895 the steamboat Norma , which had been built to haul copper ore on the Snake River above Hells Canyon, also made the run under similar circumstances. In the 1870s, Boise (to which Idaho's capital was moved in 1866) expanded rapidly as growth slowed in Lewiston. Gold drew more than 25,000 prospectors to
12649-465: The four lower Snake River dams for fish passage is a significant ongoing policy debate in the Pacific Northwest. The Snake River begins on Two Oceans Plateau near the southern border of Yellowstone National Park , about 9,200 feet (2,800 m) above sea level in the Rocky Mountains of Wyoming . From there, it flows west then south into Grand Teton National Park , where it feeds Jackson Lake ,
12788-515: The geographic depression of the eastern Snake River Plain. The gradual eastward migration of this topographic high had the effect of pushing the Continental Divide to the east. Prior to the formation of the eastern Snake River Plain, the drainage area east of about Arco, Idaho – the modern headwaters and upper course of the Snake River – flowed towards the Atlantic Ocean via the Mississippi River system. The migrating Continental Divide tilted
12927-457: The groundwater and eventually enter the river via spring flows. Excess nitrogen, phosphorus and bacterial loads occur in many locations across southern Idaho. Large algae blooms are a recurring issue in summer. The U.S. Environmental Protection Agency has established water quality guidelines for Snake River flows entering Hells Canyon, which cover bacteria, mercury, excess nutrients, pesticides, sediments and water temperature. Implementation of
13066-499: The guidelines include best management practices for agriculture and forestry, and regular water quality monitoring. Anadromous Fish migration is mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousands of kilometres. Such migrations are usually done for better feeding or to reproduce, but in other cases
13205-567: The hemp weed". Another Nez Perce name for the Snake River was Pikúunen , specifically referring to the stretch upstream of the Clearwater confluence. The Wanapum and Walla Walla people called the lower Snake River below the Clearwater Naxíyam Wána . The Shoshone called the river Yampapah , after the yampah plant that grew profusely along its banks. Downriver of Shoshone Falls, salmon and their cousins such as steelhead trout – anadromous fish which spend their adult lives in
13344-454: The land to farmers and solicited private investors to organize irrigation districts. Investors would then recoup their capital by selling water rights to farmers. Irrigation plans were reviewed by engineers, who determined the economic feasibility of the projects. Although the Carey Act saw little success in most states, it greatly benefited Idaho. Some 60 percent of all lands developed under
13483-457: The landscape of the Snake River Plain, creating the Snake River Canyon and its waterfalls, vast boulder fields, cliffs and coulees . The floodwaters then emptied through Hells Canyon; however, most evidence of their effects on the lower Snake River was erased by the much larger Missoula Floods that engulfed the Columbia Basin during the same period. Caused by the repeated collapse of an ice dam in western Montana, dozens of floods overflowed into
13622-474: 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
13761-531: The latter includes Gannett Peak , the highest point in the Snake River basin at 13,816 feet (4,211 m). Surface volcanic features – such as lava fields, cones , and thermal springs – are replete in the southern part of the Snake watershed, from Craters of the Moon National Monument northeast of Twin Falls to the Yellowstone caldera, while ancient lava flows of the Columbia River basalts underlie
13900-515: The lower Salmon River. The Northern Shoshone and the Bannock , a Northern Paiute group that became culturally associated with the Shoshone, occupied an area stretching from the Snake River Plain east to the Rocky Mountains and south towards the Great Basin, as well as valleys of the upper Salmon River. A Nez Perce name for the river was Kimooenim or variations thereof, meaning "the stream/place of
14039-481: The lower Snake River from the north, backing water as far upstream as Lewiston. The formerly west-flowing Palouse River was rerouted to flow south into the Snake River, forming Palouse Falls, whose outsized plunge pool attests to the force of the floods. Starting around the end of the last glacial period, the Snake River Plain was inhabited by hunter-gatherers of the ancient Clovis (10000–9000 BCE), Folsom (9000–8000 BCE) and Plano (8600–5800 BCE) cultures. Along
14178-603: The lower Snake River in Washington, the Marmes Rockshelter – flooded in 1968 after the construction of Lower Monumental Dam – has yielded archeological evidence of continuous human occupation from about 9000 BCE until about 1300 CE. Starting about 2200 BCE, people in the western Snake River basin began to adopt a semi-sedentary lifestyle, with an increased reliance on fish (primarily salmon) and food preservation and storage. Shoshoni -speaking peoples arrived in
14317-430: The massive Lake Bonneville , about the size of modern-day Lake Michigan . About 15,000 years ago the lip of Red Rock Pass south of present-day Pocatello, Idaho abruptly collapsed, releasing a tremendous volume of water from Lake Bonneville into the Snake River Plain. The peak of the flood was about 500 times bigger than the largest recorded flood of the Snake at Idaho Falls in modern times. The flood completely altered
14456-505: The mean monthly discharge is highest in May and June at over 100,000 cu ft/s (2,800 m /s), and lowest in September and October at less than 25,000 cu ft/s (710 m /s). Mean annual discharge also fluctuates significantly, from a record high of 86,240 cu ft/s (2,442 m /s) in 1965, to a low of 27,890 cu ft/s (790 m /s) in 1997. In southern Idaho, Snake River flows are significantly influenced by
14595-731: The mighty Snake River , which is the main factor in the creation of Hells Canyon. The Snake River is home to numerous fish species, an abundance of class I-IV rapids (some of the largest in the Pacific Northwest ), diverse wildlife and miles of systems. There is one boat ramp that is located at the upper end of the Snake River. The wildlife is made up of over 350 species and this includes big game, small game, bird, and waterfowl hunting. Trophy hunting in this area consists of elk, mountain goats, mountain lions, mule deer, whitetail deer, and black bears. These key components make Hells Canyon an outdoor recreation mecca that brings in tourists from around
14734-470: The mining industry and the difficulty of importing goods set off an agricultural boom in the Boise Valley. By the 1880s, settlers also came to the upper Snake River north of Idaho Falls, where fertile, sandy soils presented ideal conditions for the iconic russet potato ("Idaho potato"). The dry climate made irrigation necessary, and numerous private irrigation companies were formed. Private canal systems around Boise and Idaho Falls saw some success, but all
14873-597: The mouth of the Imnaha River . In the 1880s there was a short-lived homesteading boom, but the weather was unsuited to farming and ranching, and most settlers soon gave up. However, some ranchers still operate within the boundaries of the National Recreation Area. In May 1887, 34 Chinese gold miners were ambushed and killed in the area, in an event known as the Hells Canyon Massacre . No one
15012-625: The mouth of the Salmon River and below the Hells Canyon Dam. The Wild and Scenic Rivers Act of 1968 held up progress, but with the energy crisis, they were revived in 1975; these projects were sponsored by consortiums Pacific Northwest Power Company and Washington Public Power Supply System (WPPSS). At the end of that year, President Gerald Ford signed legislation to create the Hells Canyon National Recreation Area and
15151-570: The number of known species: Forage fish often make great migrations between their spawning, feeding and nursery grounds. Schools of a particular stock usually travel in a triangle between these grounds. For example, one stock of herrings have their spawning ground in southern Norway , their feeding ground in Iceland and their nursery ground in northern Norway. Wide triangular journeys such as these may be important because forage fish, when feeding, cannot distinguish their own offspring. Capelin are
15290-450: The ocean, returning to fresh water to spawn – were a key food source for indigenous peoples, and were of great cultural importance. Rituals such as the first salmon ceremony were widely observed along the Columbia, Snake and other Northwest rivers, and so were strict catch limits, such that a healthy number of salmon would survive to reach their natal streams. The Nez Perce had more than seventy permanent villages among their fishing grounds on
15429-521: The ocean. Specifically, Lake Nicaragua bull sharks migrate to the Atlantic Ocean and Zambezi bull sharks migrate to the Indian Ocean. Diel vertical migration is a common behavior; many marine species move to the surface at night to feed, then return to the depths during daytime. A number of large marine fishes, such as the tuna , migrate north and south annually, following temperature variations in
15568-551: The ocean. These are of great importance to fisheries . Freshwater (potamodromous) fish migrations are usually shorter, typically from lake to stream or vice versa, for spawning purposes. However, potamodromous migrations of the endangered Colorado pikeminnow of the Colorado River system can be extensive. Migrations to natal spawning grounds can easily be 100 km, with maximum distances of 300 km reported from radiotagging studies. Colorado pikeminnow migrations also display
15707-511: The old country. It is its lonely grandeur that impresses one so deeply; all of the other historic places have the adjuncts of civilization, and one is almost overshadowed by a city while in their presence." Most travelers on the Oregon Trail regarded the arid Snake River Plain as an obstacle to be crossed, not a land to be settled. This began to change with the Boise gold strikes, where the demands of
15846-513: The original site in 1863. A military detachment was stationed there to quell any further violence; however, tensions continued to increase, and more wagon trains and mining parties were attacked. Starting in 1864, the Snake War was fought across much of southern Idaho, with numerous battles between the U.S. Army and the Shoshone, Bannock and Paiute. By 1868, exhausted after years of fighting, Chief Pocatello and many others surrendered and relocated to
15985-524: The outflow carved Hells Canyon, emptying Lake Idaho and integrating the upper Snake and Salmon-Clearwater into a single river system. The Teton Range, a defining topographic feature of the modern Snake River headwaters, first began to rise about 10 Ma as the Teton Fault began to move, displacing the mountain block upward as the surrounding land dropped. About 2 Ma, the Hoback Fault formed east of
16124-460: The present-day confluence of the Columbia River and Salmon-Clearwater had been established, with the combined flow draining through Wallula Gap. About 2.5 Ma, Lake Idaho reached a maximum elevation of 3,600 feet (1,100 m) above modern sea level, and overflowed northward into the Salmon-Clearwater drainage near present-day Huntington, Oregon . Over a period of about two million years,
16263-540: The projects were terminated. The first river runners were on the canyon rapids by 1928. In 1975, Congress had declared 652,000 acres (264,000 ha) to be the recreational area for the Hells Canyon National Forest. There are many recreational activities available within the canyon. Activities in Hells Canyon include fishing, jet boat tours, hunting, hiking, camping, and whitewater sports (mainly rafting and kayaking ). Much of these activities rely on
16402-513: The rationale that "if there are no beavers, there will be no reason for the Yanks to come," and even if the Americans did ultimately gain control, the HBC would already have taken all the profit. Focused primarily on the upper Snake River region, the "fur desert" policy was carried out in nine expeditions from about 1824–1831 and aimed to decrease the Americans' economic interest in the Oregon Country ,
16541-550: The reasons are unclear. Fish migrations involve movements of schools of fish on a scale and duration larger than those arising during normal daily activities. Some particular types of migration are anadromous , in which adult fish live in the sea and migrate into fresh water to spawn ; and catadromous , in which adult fish live in fresh water and migrate into salt water to spawn. Marine forage fish often make large migrations between their spawning, feeding and nursery grounds. Movements are associated with ocean currents and with
16680-578: The regional slope such that drainage flowed west into Lake Idaho, whose water levels saw a significant increase about 4.5 Ma. The Snake River Plain drainage system continued to expand east, towards what is now Yellowstone National Park. During this expansion, the Snake also captured the Bear River , which was only rerouted towards its modern outlet in the Great Salt Lake Basin about 50,000 or 60,000 years ago by lava flows in southeast Idaho. In
16819-538: The right shows the main spawning grounds and larval drift routes. Capelin on the way to feeding grounds is coloured green, capelin on the way back is blue, and the breeding grounds are red. In a paper published in 2009, researchers from Iceland recount their application of an interacting particle model to the capelin stock around Iceland, successfully predicting the spawning migration route for 2008. The term highly migratory species (HMS) has its origins in Article 64 of
16958-425: The river's mouth also has a semi-arid climate, with about 10 in (250 mm) of rain and 5 in (130 mm) of snow as measured at Ice Harbor Dam. January is the coldest month with a mean temperature of 34.3 °F (1.3 °C), and July is the hottest month at 74.6 °F (23.7 °C). Semi-arid shrubland and rangeland covers about 50 percent of the Snake River watershed. Natural vegetation
17097-703: The river, Hells Canyon is one of the deepest canyons in North America, almost one-third deeper than the Grand Canyon . Within the canyon it is joined from the left by the Imnaha River , then from the right by its longest tributary, the Salmon River . Further north, it begins to form the Idaho– Washington border, and receives the Grande Ronde River from the left. From the end of Hells Canyon at Asotin, Washington , it flows north to Lewiston, Idaho , where it
17236-488: The salmon to get past. Other examples of anadromous fishes are sea trout , three-spined stickleback , sea lamprey and shad . Several Pacific salmon (Chinook, coho and Steelhead) have been introduced into the US Great Lakes, and have become potamodromous, migrating between their natal waters to feeding grounds entirely within fresh water. Remarkable catadromous migrations are made by freshwater eels. Examples are
17375-439: The south was a continuation of "Lewis's" or Salmon River. The expedition journals note the Nez Perce called it Kimooenim , although William Clark later erased mentions of the name to replace with "Lewis's". Six days later they reached the confluence of the Snake and Columbia Rivers, after noting a number of dangerous rapids as well as many native fishing sites on the lower Snake. The expedition established friendly relations with
17514-485: The summer. The Idaho State Historical Society writes that "Perrine’s venture contrasted remarkably with private canal company failures that led to congressional provision for federal reclamation projects after 1902. As a rare successful example of state supervised private irrigation development provided for in [the Carey Act] of 1894, Milner Dam and its canal system have national significance in agricultural history." With
17653-414: The surface to feed at night and sinking to lower layers of the ocean by day. Some fish such as tuna move to the north and south at different times of year following temperature gradients. The patterns of migration are of great interest to the fishing industry. Movements of fish in fresh water also occur; often the fish swim upriver to spawn, and these traditional movements are increasingly being disrupted by
17792-493: The vast region of the Pacific Northwest centering on modern-day British Columbia, Washington, Oregon and Idaho. By the time the Americans annexed Oregon Territory in 1848, beaver were nearly extirpated across much of the Rocky Mountains. Starting in the 1840s, the Oregon Trail became well established, and thousands of settlers passed through the Snake River Plain on their way to the Willamette Valley . Coming from Wyoming,
17931-568: The waters of the Pacific Ocean. Over millions of years, the volcanoes subsided and limestone built up on the underwater platforms. The basins between them were filled with sedimentary rock . Between 130 and 17 million years ago, the ocean plate carrying the volcanoes collided with and became part of the North American continent . A period of volcanic activity followed, and much of the area was covered with floods of basalt lava , which smoothed
18070-454: The watershed is barren desert, and only about 1 percent is urbanized. Most of the Snake River watershed is public land, with the U.S. Forest Service managing the Nez Perce , Clearwater , Bitterroot , Umatilla , Wallowa–Whitman , Payette , Boise , Salmon–Challis , Sawtooth , Caribou–Targhee and Bridger–Teton National Forests that cover much of the northern and eastern parts of
18209-450: The watershed. The forests contain numerous designated wilderness areas, including the Sawtooth , Selway–Bitterroot , Frank Church-River of No Return , Gospel Hump , Hells Canyon , Teton and Gros Ventre . National Park Service land includes Craters of the Moon National Monument and Yellowstone and Grand Teton National Parks. Large areas of privately owned farmland are concentrated in
18348-439: 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
18487-490: The western part of the watershed. The Snake River Plain is the largest area without mountains, but it still features rugged terrain, being crisscrossed by canyons formed by the Snake River and its tributaries. Due to the rain shadow effect of the Cascades , precipitation as a whole is scant, averaging 14 inches (360 mm) across the entire watershed. Most precipitation falls at higher elevations as snow, thus, most runoff in
18626-527: The world. Hells canyon offers tours year round, while most of the whitewater activities peak in summer months. To participate in these recreational activities one can utilize commercial charters or private trips. There are three roads that lead to the Snake River and they are located between Hells Canyon Dam and the Oregon-Washington state line. There are no roads that cross Hells Canyon. From Oxbow Bridge near Copperfield, Oregon , Hells Canyon Road follows
18765-421: The year, increasing about 20 percent during snowmelt and decreasing about 20 percent with late summer irrigation diversions. Despite its great length, the Snake River accumulates most of its water in the lower one-fourth of its course. By the time it reaches Hells Canyon Dam , 247 miles (398 km) from the mouth, the mean annual discharge is about 19,000 cu ft/s (540 m /s) – just over
18904-475: Was commissioned to haul supplies up the Snake River to Fort Taylor. Captained by veteran Oregon river pilot Len White, the Wright was the first steamboat to run on the Snake River and the Columbia above The Dalles . Two years later, Elias D. Pierce discovered gold to the east on Nez Perce treaty land. As thousands of fortune seekers flocked to the area, the city of Lewiston was founded in 1861, in violation of
19043-529: Was held accountable. Groups of white men ambushed the Chinese gold miners because of an Anti-Chinese movement that made its way to Oregon. After completion of large hydropower dams on the Columbia River in the 1930s through the 1950s, several entities sought approval from the Federal Power Commission to build dams on the Snake River, including a high dam in Hells Canyon. In 1955, the commission issued
19182-452: Was performed by Wang et al. (2019) to identify more potential Mx genes that resided in rainbow trout. An additional six Mx genes were identified in that study, now named Mx4-9. They also concluded that the trout Mx genes were "differentially expressed constitutively in tissues" and that this expression is increased during development. The Mx gene family is expressed at high levels in the blood and intestine during development, suggesting they are
19321-559: Was the same or similar to the Plains Indian common sign for "snake." The English name for the river was likely derived from this interpretation of the hand gesture, although it is uncertain when the name was first used. The first Euro-Americans to reach the Snake River watershed were the Lewis and Clark Expedition, who in August 1805 crossed the Continental Divide at Lemhi Pass and descended to
#367632