Pierre, South Dakota Pierre, South Dakota Pierre (; Lakota: "čhúŋkaške", "fort") is the state capital of the U.S. state of South Dakota, and the county seat of Hughes County. The population was 13,646 at the 2010 census, making it the second-least populous state capital in the United States after Montpelier, Vermont, and the eighth-most populous city in South Dakota. Founded in 1880 on the east bank of the Missouri River opposite Fort Pierre, Pierre has been the state capital since South Dakota gained statehood on November 2, 1889. It was challenged by Huron for the capital and won because of its location in
South Dakota Highway 15 1976, when many of the suffixed state routes were eliminated, this route was redesignated as SD 123. South Dakota Highway 15Y (SD 15Y) was a short state highway in the northeastern part of the U.S. state of South Dakota. It was established in the early 1960s, from US 12 in Big Stone City to SD 15 southwest of Shady Beach. In 1976, it was redesignated as SD 109. South Dakota Highway 15 South Dakota Highway 15 (SD 15) is a state highway in the northeastern part of the U.S. state of South Dakota. It connects Clear Lake, Milbank, and Wilmot.