Clearwater River (Idaho)

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Clearwater River
ClearwaterRiver nearGreerID.jpg
Clearwater River near Greer Ferry
Map showing the Clearwater River watershed
Native nameKooskooskia
Country United States
State Idaho
Region Idaho County, Clearwater County, Shoshone County, Nez Perce County
Cities Orofino, Lewiston
Physical characteristics
Source Middle Fork Clearwater River
  locationConfluence of Selway River and Lochsa River, Idaho County
  coordinates 46°08′28″N115°35′53″W / 46.14111°N 115.59806°W / 46.14111; -115.59806
  elevation1,453 ft (443 m)
2nd source South Fork Clearwater River
  locationNear Red River Hot Springs, Idaho County
  coordinates 45°52′09″N115°18′32″W / 45.86917°N 115.30889°W / 45.86917; -115.30889
  elevation4,285 ft (1,306 m)
Source confluenceKooskia
  location Idaho County
  coordinates 46°08′45″N115°58′56″W / 46.14583°N 115.98222°W / 46.14583; -115.98222
  elevation1,220 ft (370 m)
Mouth Snake River
Lewiston, Nez Perce County
46°25′30″N117°02′14″W / 46.42500°N 117.03722°W / 46.42500; -117.03722 Coordinates: 46°25′30″N117°02′14″W / 46.42500°N 117.03722°W / 46.42500; -117.03722
741 ft (226 m)
Length74.8 mi (120.4 km), Southeast-northwest [1]
Basin size9,645 sq mi (24,980 km2)
  average15,300 cu ft/s (430 m3/s)
  maximum109,000 cu ft/s (3,100 m3/s) [2]
Basin features
River system Snake River
  left South Fork Clearwater River
  right Middle Fork Clearwater River, North Fork Clearwater River, Potlatch River

The Clearwater River is in the northwestern United States, in north central Idaho. Its length is 74.8 miles (120.4 km), [1] it flows westward from the Bitterroot Mountains along the Idaho-Montana border, and joins the Snake River at Lewiston. In October 1805, the Lewis and Clark Expedition descended the Clearwater River in dugout canoes, putting in at "Canoe Camp,"five miles (8 km) downstream from Orofino; they reached the Columbia Bar and the Pacific Ocean about six weeks later.


By average discharge, the Clearwater River is the largest tributary of the Snake River. The River got its name for the Niimiipuutímt naming as Koos-Koos-Kai-Kai - "clear water". [3]

The drainage basin of the Clearwater River is 9,645 square miles (24,980 km2). Its mean annual discharge is 15,300 cubic feet per second (430 m3/s) [4]


At the small town of Kooskia, the Middle Fork and South Fork of the Clearwater River join their waters to form the main stem of the Clearwater. The larger Middle Fork is made up of the combined flows of the Lochsa and Selway rivers which flow from the Bitterroot Mountains located to the east, while the much smaller South Fork originates in the Selway-Bitterroot Wilderness to the south. From the confluence the Clearwater flows northwest, passing the Heart of the Monster site of the Nez Perce National Historical Park. U.S. Route 12 follows the river to Kamiah, where it is joined by Lawyer Creek from the southwest.

The river then continues northwest through a canyon to the confluence with Lolo Creek from the east. It soon passes the town of Greer and receives Jim Ford Creek from the east. At Orofino, the river gains the waters of Orofino Creek and swings westward in a nearly straight line for about three miles (5 km), then receives the North Fork from the northeast at Ahsahka, close to Dworshak Reservoir. After the North Fork contributes its flow, the Clearwater continues west and receives Big Canyon Creek from the south, and Bedrock Creek from the north.

As the river canyon cuts deeper into the Columbia Plateau, the Clearwater passes the unincorporated communities of Lenore and Myrtle, where it receives Cottonwood Creek from the southeast, and Arrow, where it receives the Potlatch River from the north. Lapwai Creek joins from the south where the river passes close to Spalding. Here, U.S. Route 95 crosses the Clearwater and is co-signed with U.S. Route 12 along the river's north bank for several miles. The river soon widens and slows into the slack water of Lower Granite Lake as it approaches Lewiston. Just as it crosses the Idaho-Washington state line, it joins its waters with the Snake River.


The Clearwater breaks into several separate forks:

Clearwater River near Orofino, ID Clearwater River in Ahsahka, Idaho.jpg
Clearwater River near Orofino, ID

River modifications

The Dworshak Reservoir is the only major lake on the Clearwater system, created from the Dworshak Dam, completed in the early 1970s. Dworshak Dam is on the North Fork of the Clearwater River, and is just northwest of Orofino. There is no fish ladder; the dam blocks salmon and steelhead passage.


The border between Washington and Idaho was defined as the meridian running north from the confluence of the Clearwater River and the Snake River. Although this border is often referred to as the 117th meridian west longitude, the actual border line is slightly west (less than 2 miles) of the 117th meridian. [5]

See also

Related Research Articles

Nez Perce Indigenous peoples of North America

The Nez Perce are an Indigenous people of the Plateau who are presumed to have lived on the Columbia River Plateau in the Pacific Northwest region for at least 11,500 years.

Clearwater County, Idaho County in Idaho, US

Clearwater County is a county located in the U.S. state of Idaho. As of the 2010 census, the population was 8,761. The county seat is Orofino. Established in 1911, the county was named after the Clearwater River.

Orofino, Idaho Town in Idaho, United States

Orofino is a town in and the county seat of Clearwater County, Idaho, along Orofino Creek and the north bank of the Clearwater River. It is the major city within the Nez Perce Indian Reservation. The population was 3,142 at the time of the 2010 census.

Kooskia, Idaho City in Idaho, United States

Kooskia is a city in Idaho County, Idaho, United States. It is at the confluence of the South and Middle forks of the Clearwater River, combining to become the main river. The population was 607 at the 2010 census, down from 675 in 2000.

North Central Idaho

North Central Idaho is an area which spans the central part of the state of Idaho and borders Oregon, Montana, and Washington. It is the southern half of the Idaho Panhandle region and is rich in agriculture and natural resources. Lewis and Clark travelled through this area on their journey to the Pacific Ocean in 1805-06. The primary cities in this region are Lewiston and Moscow, home of the University of Idaho.

Selway–Bitterroot Wilderness

The Selway–Bitterroot Wilderness is a protected wilderness area in the states of Idaho and Montana, in the northwestern United States.

Dworshak National Fish Hatchery

Dworshak National Fish Hatchery is a mitigation hatchery located on the Clearwater River within the Nez Perce Reservation near Ahsahka, in north-central Idaho, United States. It was constructed in 1969 by the Army Corps of Engineers, and is co-managed by the U.S. Fish and Wildlife Service and the Nez Perce Tribe. The hatchery is one of the largest combination producers of anadromous (migratory) fish in the world. These fish make a 1000-mile round trip to the ocean and back to spawn in the Clearwater River. The Dworshak Dam blocks access to the historical spawning areas on the North Fork-Clearwater River for the steelhead, and it is too high for a fish ladder.

Clearwater National Forest National forest in Idaho, United States

Clearwater National Forest with headquarters on the Nez Perce Reservation at Kamiah is located in North Central Idaho in the northwestern United States. The forest is bounded on the east by the state of Montana, on the north by the Idaho Panhandle National Forest, and on the south and west by the Nez Perce National Forest and Palouse Prairie.

Dworshak Dam Dam in Clearwater County, Idaho

Dworshak Dam is a concrete gravity dam in the western United States, on the North Fork Clearwater River in Clearwater County, Idaho. The dam is located approximately four miles (6 km) northwest of Orofino and impounds the Dworshak Reservoir for flood control and hydroelectricity generation. With a height of 717 feet (219 m), Dworshak is the third tallest dam in the United States and the tallest straight-axis concrete dam in the Western Hemisphere. Lacking fish ladders, Dworshak Dam blocks fish passage and completely extirpated anadromous fish migration into the upper reaches of the North Fork Clearwater River and its tributaries in Idaho. Construction of the dam by the U.S. Army Corps of Engineers (USACE) began in 1966 and was completed in 1973.

Dent Bridge

The Dent Bridge is a suspension bridge in the northwest United States, located in north central Idaho in Clearwater County, north of Orofino. It is 17 miles (27 km) up the North Fork of the former Clearwater River, now the Dworshak Reservoir. Completed 50 years ago in 1971 at a cost of $7,848,950, it has a main span of 1,050 feet (320 m), and an overall length of 1,550 feet (472 m).

Lochsa River

The Lochsa River is in the northwestern United States, in the mountains of north central Idaho. It is one of two primary tributaries of the Middle Fork of the Clearwater River in the Clearwater National Forest. Lochsa is a Nez Perce word meaning rough water. The Salish name is Ep Smɫí, "It Has Salmon."

Selway River

The Selway River is a large tributary of the Middle Fork of the Clearwater River in the U.S. state of Idaho. It flows within the Selway-Bitterroot Wilderness, the Bitterroot National Forest, and the Nez Perce National Forest of North Central Idaho. The entire length of the Selway was included by the United States Congress in 1968 as part of the National Wild and Scenic Rivers Act.

U.S. Route 12 is a federal highway in north central Idaho. It extends 174.210 miles (280.364 km) from the Washington state line in Lewiston east to the Montana state line at Lolo Pass, generally along the route of the Lewis and Clark expedition, and is known as the Northwest Passage Scenic Byway It was previously known as the Lewis and Clark Highway.

North Fork Clearwater River

The North Fork Clearwater River is a major tributary of the Clearwater River in the U.S. state of Idaho. From its headwaters in the Bitterroot Mountains of eastern Idaho, it flows 135 miles (217 km) westward and is dammed by the Dworshak Dam just above its mouth in north-central Idaho. Draining a rugged watershed of 2,462 square miles (6,380 km2), the river has an average flow of over 5,600 cubic feet per second (160 m3/s), accounting for a third of the discharge from the Clearwater basin. The river drains parts of Clearwater, Shoshone, Latah, and Idaho counties. Most of the watershed is managed by the U.S. Forest Service. Some of the fish of the river include westslope cutthroat trout, rainbow trout, mountain whitefish, and the threatened bull trout. It also has smallmouth bass and a kokanee salmon run, both from Dworshak Reservoir. The North Fork drainage is home to grizzly bears, cougars, deer, moose, black bear, elk, grey wolves, and osprey. The river used to have a large steelhead run before the implementation of Dworshak Dam. The North Fork of the Clearwater is located within the Clearwater National Forest

Middle Fork Clearwater River

The Middle Fork Clearwater River is a short, but high volume river in northern Idaho and is the major source of the Clearwater River, a tributary of the Snake River. The Middle Fork flows west for 23 miles (37 km) from the confluence of the Selway River and Lochsa River at Lowell, to the town of Kooskia where it joins with the South Fork Clearwater River to create the Clearwater River. The Middle Fork's entire length is within Idaho County, although a small portion of its watershed extends into Clearwater County.

South Fork Clearwater River

The South Fork Clearwater River is a 62-mile (100 km) long river in north-central Idaho in the United States. Draining about 1,175 square miles (3,040 km2), the South Fork joins with the Middle Fork Clearwater River to form the Clearwater River, a major tributary of the Snake River.

Lowell, Idaho Unincorporated community in Idaho, United States

Lowell is an unincorporated community in Idaho County, Idaho, United States, located at the confluence of the Selway and Lochsa rivers, where they join to form the Middle Fork of the Clearwater River. The community lies within the Nez Perce-Clearwater National Forests at an elevation of 1,486 feet (453 m) above sea level, and was named after Henry Lowell, its first postmaster.

Kooskia Internment Camp

The Kooskia Internment Camp is a former internment camp in the northwest United States, located in north central Idaho, about thirty miles (50 km) northeast of Kooskia in northern Idaho County. It operated during the final two years of World War II.

Syringa is an unincorporated town in Idaho County, Idaho, United States. The town is named for the shrub which grows in the area [Philadelphus lewisii], and is the Idaho State Flower. It is in the Pacific Time Zone,. The climate is mild with an average precipitation of over 25 inches per year.


  1. 1 2 U.S. Geological Survey. National Hydrography Dataset high-resolution flowline data. "The National Map". Archived from the original on 2012-04-05.CS1 maint: discouraged parameter (link), accessed May 3, 2011
  2. "USGS Gage #13343000 on the Clearwater River near Lewiston". National Water Information System. United States Geological Survey . Retrieved 2010-03-09.CS1 maint: discouraged parameter (link)
  3. Rees, John E. (1918). Idaho Chronology, Nomenclature, Bibliography. W.B. Conkey Company. p.  64.
  4. "Clearwater Subbasin Plan" (PDF). Archived from the original (PDF) on 2007-12-17. Retrieved 2008-09-13., Northwest Power and Conservation Council
  5. "Washington State Constitution". Archived from the original on 2005-12-24.CS1 maint: discouraged parameter (link) Article XXIV Boundaries