Umatilla River

Umatilla River
The Umatilla River, flowing through northern Pendleton, July 2005
Location of the mouth of the Umatilla River in Oregon
EtymologyNative American (Indian) name for the river
Location
CountryUnited States
StateOregon
CountyUmatilla
Physical characteristics
SourceConfluence of north and south forks
  locationBlue Mountains
  coordinates45°43′32″N 118°11′17″W / 45.72556°N 118.18806°W / 45.72556; -118.18806
  elevation2,332 ft (711 m)
MouthColumbia River
  location
Umatilla, Oregon
  coordinates
45°55′09″N 119°21′20″W / 45.91917°N 119.35556°W / 45.91917; -119.35556
  elevation
269 ft (82 m)
Length89 mi (143 km)
Basin size2,450 sq mi (6,300 km2)
Discharge 
  locationnear Umatilla, 2.1 miles (3.4 km) from the mouth
  average494 cu ft/s (14.0 m3/s)
  minimum0 cu ft/s (0 m3/s)
  maximum19,800 cu ft/s (560 m3/s)

The Umatilla River is an 89-mile (143 km) tributary of the Columbia River in northern Umatilla County, Oregon, United States. Draining a basin of 2,450 square miles (6,300 km2), it enters the Columbia near the city of Umatilla in the northeastern part of the state. In downstream order, beginning at the headwaters, major tributaries of the Umatilla River are the North Fork Umatilla River and the South Fork Umatilla River, then Meacham, McKay, Birch, and Butter creeks.

The name Umatilla is derived from the Native American autonym of the people residing along its banks - the Umatilla, which called themselves Imatalamłáma - "People from the Village Ímatalam [on the Peninsula formed by the confluence of Umatilla River with the Columbia]", which was first recorded as Youmalolam in the journals of the Lewis and Clark Expedition and spelled in many other ways in early books about Oregon.

Today the river is also called Nixyáawi wána in the Umatilla language, meaning "Pendleton area River, i.e. Umatilla River".