Knife River was a census-designated place (CDP) in Richland County, Montana, United States.

[2] The Knife River CDP was located at 47°27′13″N 104°20′42″W / 47.45361°N 104.34500°W / 47.45361; -104.34500 (47.453610, -104.344938),[3] comprising the community of Savage and agricultural areas to the east and west.

According to the United States Census Bureau, the CDP has a total area of 3.5 square miles (9.1 km2), all land.

36.0% of all households were made up of individuals, and 19.2% had someone living alone who was 65 years of age or older.

About 10.1% of families and 15.8% of the population were below the poverty line, including 16.5% of those under the age of eighteen and 24.4% of those 65 or over.