Palouse River

Palouse River
Several miles downstream from its fork in Colfax; looking west in 2007
Palouse River's mouth in Washington
Location
CountryUnited States
StateWashington, Idaho
CountyFranklin, Whitman, Adams, Latah
Physical characteristics
SourceRocky Mountains
  coordinates46°58′07″N 116°27′31″W / 46.9685°N 116.4587°W / 46.9685; -116.4587
MouthSnake River
  coordinates
46°35′24″N 118°12′55″W / 46.59000°N 118.21528°W / 46.59000; -118.21528
  elevation
541 ft (165 m)
Length167 mi (269 km)
Basin size3,303 sq mi (8,550 km2)
Discharge 
  locationriver mile 19.6 at Hooper
  average599 cu ft/s (17.0 m3/s)
  minimum0 cu ft/s (0 m3/s)
  maximum33,500 cu ft/s (950 m3/s)

The Palouse River is a tributary of the Snake River in Washington and Idaho, in the northwest United States. It flows for 167 miles (269 km) southwestwards, primarily through the Palouse region of southeastern Washington. It is part of the Columbia River Basin, as the Snake River is a tributary of the Columbia River.

Its canyon was carved out by a fork in the catastrophic Missoula Floods of the previous ice age, which spilled over the northern Columbia Plateau and flowed into the Snake River, eroding the river's present course in a few thousand years.