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.
Sun River is located at 47°31′55″N 111°43′47″W / 47.53194°N 111.72972°W / 47.53194; -111.72972 (47.531915, -111.729648).
According to the United States Census Bureau, the CDP has a total area of 1.8 square miles (4.7 km²), all of it land.
As of the census of 2000, there were 500 people, 230 households, and 58 families residing in the CDP. The population density was 98.8 people per square mile (27.9/km²). There were 65 housing units at an average density of 35.8 per square mile (13.9/km²). The racial makeup of the CDP was 96.95% White, 2.29% Native American, and 0.76% from two or more races.
There were 58 households out of which 27.6% had children under the age of 18 living with them, 53.4% were married couples living together, 5.2% had a female householder with no husband present, and 36.2% were non-families. 31.0% of all households were made up of individuals and 8.6% had someone living alone who was 65 years of age or older. The average household size was 2.26 and the average family size was 2.84.
In the CDP, the population was spread out with 26.0% under the age of 18, 5.3% from 18 to 24, 23.7% from 25 to 44, 27.5% from 45 to 64, and 17.6% who were 65 years of age or older. The median age was 39 years. For every 100 females, there were 92.6 males. For every 100 females age 18 and over, there were 94.0 males.
The median income for a household in the CDP was $25,357, and the median income for a family was $28,750. Males had a median income of $24,583 versus $19,531 for females. The per capita income for the CDP was $14,647. There were 13.5% of families and 10.2% of the population living below the poverty line, including 14.7% of under eighteens and 14.3% of those over 64.