About This Place
Fort Thompson is a census-designated place (CDP) in Buffalo County, South Dakota, United States. The population was 1,282 at the 2010 census, making it the largest settlement on the Crow Creek Reservation.
Fort Thompson is located at 44°3′39″N 99°25′45″W / 44.06083°N 99.42917°W / 44.06083; -99.42917 (44.060793, -99.429128).
According to the United States Census Bureau, the CDP has a total area of 12.6 square miles (32.6 km²), of which, 10.3 square miles (26.7 km²) of it is land and 2.3 square miles (5.9 km²) of it (17.98%) is water.