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 87 of Hill City. South Dakota Highway 87 South Dakota Highway 87 (SD 87) is a state highway in the southwestern part of the U.S. state of South Dakota. It travels through the Black Hills region. The highway's southern terminus is at an intersection with U.S. Route 385 (US 385), about southeast of Pringle, within the southwestern part of Wind Cave National Park. Its northern terminus is at an intersection with US 16/US 385 about south-southwest of Hill City, within the east-central part of the Black Hills National Forest. The highway travels through Wind Cave National Park and Custer State Park.