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 36 in 1926. At that time, it continued further west to the Wyoming border, utilizing the current route of US 16A to Custer, and U.S. Route 16 west of Custer; US 16 went northwest from Rapid City. The western terminus was pulled back to its present location around 1935, when US 16 was rerouted southwest through the Black Hills. In 1933 and 1934, this route was also part of U.S. Route 216, which then continued north to Rapid City. South Dakota Highway 36 South Dakota Highway 36 (SD 36) is an east–west state route located in southwest South Dakota. It begins