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 79 with U.S. Route 212 south of Newell. Near North Dakota, the highway passes through the South Dakota portion of Custer National Forest. SD 79 then joins SD 20 for a short concurrent run, and finally turns northward until it reaches North Dakota. South Dakota Highway 79 South Dakota Highway 79 (SD 79) is a state highway in the U.S. state of South Dakota. It runs from Maverick Junction near the Black Hills National Forest to the North Dakota state line. SD 79's southern terminus is at Maverick Junction near Hot Springs, where it meets US 18 and US 385. SD