Lochsa River

Lochsa River
Headwaters near Powell in 2008
Lochsa and Selway rivers
Lochsa River is located in Idaho
Lochsa River
Location of the mouth of the Lochsa River in Idaho
Lochsa River is located in the United States
Lochsa River
Lochsa River (the United States)
EtymologyNez Perce word for "rough water"
Location
CountryUnited States of America
StateIdaho
CountyIdaho
Physical characteristics
SourceConfluence of Crooked Fork and Colt Killed Creek,
Bitterroot Mountains
 • locationNear Powell Ranger Station, Idaho County, Idaho
 • coordinates46°30′30″N 114°40′54″W / 46.50833°N 114.68167°W / 46.50833; -114.68167[1]
 • elevation3,441 ft (1,049 m)[2]
MouthClearwater River
 • location
Lowell, Idaho County, Idaho
 • coordinates
46°08′25″N 115°35′58″W / 46.14028°N 115.59944°W / 46.14028; -115.59944[1]
 • elevation
1,453 ft (443 m)[1]
Length70.1 mi (112.8 km)[3]
Basin size1,180 sq mi (3,100 km2)[4]
Discharge 
 • locationLowell, 0.9 miles (1.4 km) from mouth[5]
 • average2,822 cu ft/s (79.9 m3/s)[5]
 • minimum100 cu ft/s (2.8 m3/s)
 • maximum35,100 cu ft/s (990 m3/s)
TypeRecreational
DesignatedOctober 2, 1968
Reference no.P.L. 90-542

The Lochsa River is in the northwestern United States, in the mountains of north central Idaho. It is one of two primary tributaries (with the Selway to the south) of the Middle Fork of the Clearwater River in the Clearwater National Forest. Lochsa is a Nez Perce word meaning rough water.[6][7] The Salish name is Ep Smɫí, "It Has Salmon."[8]

The Lochsa (pronounced "lock-saw") was included by the U.S. Congress in 1968 as part of the National Wild and Scenic Rivers Act.[9][10] The Lochsa and Selway rivers and their tributaries have no dams, and their flow is unregulated. In late spring (mid-May to mid-June), the Lochsa River is rated as one of the world's best for continuous whitewater.

The main stem of the Lochsa is seventy miles (110 km) in length from its headwaters near Powell Ranger Station in the Bitterroots to Lowell, where the Lochsa joins the Selway River to form the Middle Fork of the Clearwater.[3] Over this distance, the river drops nearly two thousand feet (600 m), from 3,441 feet (1,049 m) above sea level at Powell to 1,453 feet (443 m) at Lowell.[1]

The drainage basin for the Lochsa River system covers 1,180 square miles (3,060 km2) in Idaho County.[4] The river is fed by the melting of the significant snowpack of the Bitterroot Range, among the highest precipitation areas in the state.[11]

  1. ^ a b c d "Lochsa River". Geographic Names Information System (GNIS). United States Geological Survey (USGS). June 21, 1979. Retrieved July 26, 2008.
  2. ^ Source elevation derived from Google Earth using Geographic Names Information System (GNIS) source coordinates.
  3. ^ a b Rocky Point Quadrangle, Idaho, 7.5-Minute Series (Topographic) (Map) (1994 ed.). USGS and United States Forest Service.
  4. ^ a b "USGS 13337000 Lochsa River near Lowell ID". USGS. 2008. Retrieved July 27, 2008.
  5. ^ a b The average discharge rate was calculated by adding the average annual discharge rates at the USGS gauge at Lowell for the 77 calendar years, 1930–2006 and dividing by 77.
  6. ^ Space, Ralph S. (2001). The Lolo Trail, second edition. Missoula: Historic Montana Publishing. p. 21. ISBN 0-9663355-2-X.
  7. ^ "Lochsa River Canyon". Discovering Lewis & Clark. VIAs, Inc. 1998. Retrieved July 30, 2008.
  8. ^ "Salish Audio Files". Salish-Pend d'Oreille Culture Committee. 2014. Retrieved 2014-06-28.
  9. ^ Cite error: The named reference Highway 12 was invoked but never defined (see the help page).
  10. ^ Hewlett, Frank (October 3, 1968). "Cascades park bill signed". Spokesman-Review. (Spokane, Washington). p. 8.
  11. ^ "Annual Average Precipitation". Idaho Department of Water Resources. (Idaho map). Retrieved August 1, 2018.