South Dakota South Dakota South Dakota () is a U.S. state in the Midwestern region of the United States. It is named after the Lakota and Dakota Sioux Native American tribes, who compose a large portion of the population and historically dominated the territory. South Dakota is the seventeenth largest by area, but the fifth smallest by population and the 5th least densely populated of the 50 United States. As the southern part of the former Dakota Territory, South Dakota became a state on November 2, 1889, simultaneously with North Dakota. Pierre is the state capital and Sioux Falls, with a population
South Dakota Highway 89 The section of SD 89 from Custer to Sylvan Lake was once part of US 85 Alternate. South Dakota Highway 89 South Dakota Highway 89 (SD 89) is a state highway in the southwestern part of the U.S. state of South Dakota. The highway travels from U.S. Route 18 (US 18) near Minnekahta to SD 87 in Custer State Park. SD 89 is concurrent with US 385 from Pringle to Custer. The portion of the highway from Custer to SD 87 is part of the Peter Norbeck Scenic Byway. SD 89 was established in 1950 from Spearfish to Minnekahta. The