Yakima River

Yakima River
State Route 10 winds past the Yakima River near the town of Thorp.
Map of the Yakima River watershed
Location
CountryUnited States
StateWashington
CitiesCle Elum, Ellensburg, Yakima, Sunnyside, Richland
Physical characteristics
SourceKeechelus Lake
  locationKittitas County, Washington
  coordinates47°19′20″N 121°20′21″W / 47.32222°N 121.33917°W / 47.32222; -121.33917
  elevation2,520 ft (770 m)
MouthColumbia River at Lake Wallula
  location
Richland, Benton County, Washington
  coordinates
46°15′10″N 119°13′51″W / 46.25278°N 119.23083°W / 46.25278; -119.23083
  elevation
344 ft (105 m)
Length214 mi (344 km)
Basin size6,150 sq mi (15,900 km2)
Discharge 
  locationKiona, RM 30
  average3,493 cu ft/s (98.9 m3/s)
  minimum225 cu ft/s (6.4 m3/s)
  maximum59,400 cu ft/s (1,680 m3/s)
Discharge 
  locationMabton, RM 60
  average3,311 cu ft/s (93.8 m3/s)
Discharge 
  locationUnion Gap, RM 107
  average3,542 cu ft/s (100.3 m3/s)
Discharge 
  locationUmtanum, RM 140
  average2,430 cu ft/s (69 m3/s)
Basin features
Tributaries 
  leftCle Elum River, Teanaway River
  rightNaches River

The Yakima River is a tributary of the Columbia River in south central and eastern Washington state, named for the indigenous Yakama people. Lewis and Clark mention in their journals that the Chin-nâm pam (or the Lower Snake River Chamnapam Nation) called the river Tâpe têtt (also rendered Tapteete), possibly from the French tape-tête, meaning "head hit". The length of the river from headwaters to mouth is 214 miles (344 km), with an average drop of 9.85 feet per mile (1.866 m/km). It is the longest river entirely in Washington state.