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 71 South Dakota Highway 71 South Dakota Highway 71 (SD 71) is a state highway in the southwestern part of the U.S. state of South Dakota. It travels from the Nebraska state line, where it continues as N-2/N-71, through the Black Hills National Forest, to U.S. Route 18 Bypass (US 18 Byp.) in Hot Springs. The road was originally a part of SD 87. It became SD 71 in 1962. SD 71's southern terminus is at the Nebraska border in Black Hills National Forest where it has the same number. In the forest, the route meets the terminus of South Dakota