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 21 South Dakota Highway 21 South Dakota Highway 21 (SD 21) is a state highway in the eastern part of the U.S. state of South Dakota. It connects Lake Norden and Hayti, completely within the south-central part of Hamlin County. SD 21 originally extended from the Nebraska state line to the North Dakota state line, completely concurrent with U.S. Route 81 (US 81). By the mid-1930s, only the current part of the highway remained. SD 21 begins at an intersection with SD 28 just northwest of the main part of Lake Norden. It travels to the north. Almost immediately, it crosses