Hughes County, South Dakota Hughes County, South Dakota Hughes County is a county located in the U.S. state of South Dakota. As of the 2010 census, the population was 17,022, making it the least populous capital county in the nation, and the twelfth-most populous county in South Dakota. Its county seat is Pierre, the state capital. The county was created in 1873 and organized in 1880. It was named for Alexander Hughes, a legislator. Hughes County is part of the Pierre, SD Micropolitan Statistical Area. According to the U.S. Census Bureau, the county has a total area of , of which is land and
South Dakota Highway 123 South Dakota Highway 123 South Dakota Highway 123 (SD 123) is a state highway in the U.S. state of South Dakota that runs from U.S. Route 12 (US 12) near Marvin to SD 15 in Wilmot. It is maintained by the South Dakota Department of Transportation (SDDOT), and is not part of the National Highway System. SD 123 begins at an intersection with US 12 east of Marvin in Grant County and begins north through open plains. The highway enters Roberts County north of its southern terminus and continues north through rolling farmland. North of the county line, the route