South Dakota is a 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 17th most expansive, but the 5th least populous and the 5th least densely populated of the 50 United States. Once the southern part of the 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 of about 171,000, is South Dakota's largest city.South Dakota is bordered by the states of North Dakota (on the north), Minnesota (to the east), Iowa (to the southeast), Nebraska (on the south), Wyoming (on the west), and Montana (to the northwest). The state is bisected by the Missouri River, dividing South Dakota into two geographically and socially distinct halves, known to residents as "East River" and "West River".
