Mound City, SD
Mound City is a town in Campbell County, South Dakota, United States. The population was 71 at the 2010 census. It is the county seat of Campbell County.
Mound City is located at 45°43′33″N 100°4′10″W / 45.72583°N 100.06944°W / 45.72583; -100.06944 (45.725799, -100.069562).
According to the United States Census Bureau, the town has a total area of 0.1 square miles (0.3 km²), all of it land.