The county in which Sun River Montana is located is ranked as the what most populous county in Montana?
Sun River, Montana Sun River is a census-designated place (CDP) in Cascade County, Montana, United States. The population was 124 at the 2010 census. It is part of the Great Falls, Montana Metropolitan Statistical Area.
Routt County, Colorado Routt County is one of the 64 counties in the U.S. state of Colorado. As of the 2010 census, the population was 23,509. The county seat is Steamboat Springs.