Fort Smith is a census-designated place in Big Horn County, Montana, United States. The population was 161 at the 2010 census. The town is named for the former Fort C.F. Smith.Fort Smith is located at 45°18′28″N 107°55′39″W / 45.307906°N 107.927392°W / 45.307906; -107.927392.According to the United States Census Bureau, the CDP has a total area of 1.7 square miles, of which 1.4 square miles is land and 0.23 square miles, or 14.90%, is water. It is located along the Bighorn River where it exits from Bighorn Canyon. Montana Highway 313 ends at Fort Smith and leads northeast 42 miles to Hardin and Interstate 90.As of the census of 2000, there were 122 people, 51 households, and 31 families residing in the CDP. The population density was 103.6 people per square mile. There were 143 housing units at an average density of 121.4/sq mi. The racial makeup of the CDP was 64.75% White, 32.79% Native American, 2.46% from other races. Hispanic or Latino of any race were 4.92% of the population.