Metolius is a city in Jefferson County, Oregon, United States, named for the Metolius River, a nearby tributary of the Deschutes River. The na…Metolius is a city in Jefferson County, Oregon, United States, named for the Metolius River, a nearby tributary of the Deschutes River. The name for both comes from the Warm Springs or Sahaptin word mitula, meaning white salmon and referring to a light colored Chinook salmon and not a whitefish. The population was 710 at the 2010 census.