Geography of South Dakota of the federal or state government, such as Badlands National Park, Wind Cave National Park, and Custer State Park, are located in the state. In 2011, the population of South Dakota was estimated to be 824,082, and the state ranks fifth-lowest in both total population as well as population density in the United States. Sioux Falls, with a population of just over 170,000, is the largest city in the state. Rapid City ranks as South Dakota's second-largest city, and Pierre is the state capital. Historically a very agricultural state, the service and tourism sectors have grown in economic importance in
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