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 71 Highway 471. After that, it leaves the forest and ends at US 18 Byp. in Hot Springs. The road was originally commissioned in 1936 as part of South Dakota Highway 87. Part of that highway was given the SD 71 designation in 1962. South Dakota Highway 71 South Dakota Highway 71 (SD 71) is a state highway in the southwestern part of the U.S. state of South Dakota. It travels from the Nebraska state line, where it continues as N-2/N-71, through the Black Hills National Forest, to U.S. Route 18 Bypass (US 18 Byp.) in Hot Springs. The road was