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 30 segment extended from US 77, west of White, to the Minnesota state line. Both segments were connected by 1960. Nearly the entire highway west of US 77, which is now I-29, was decommissioned by 1965. South Dakota Highway 30 South Dakota Highway 30 (SD 30) is a state highway in the east-central part of the U.S. state of South Dakota. It connects the north-central part of Brookings with the northeastern part of it. SD 30 was established in the mid-1950s. It had two segments, which were connected by the end of the decade. However, most of the highway west of