South Dakota is a Midwestern state in the United States. It is named after the Lakota and Dakota (Sioux) American Indian tribes. South Dakota was admitted to the Union on November 2, 1889. North Dakota was admitted on the same day. South Dakota is probably best known as the location of Mount Rushmore.

South Dakota is bordered to the north by North Dakota; to the south by Nebraska; to the east by Iowa and Minnesota; and to the west by Wyoming and Montana. It is one of the six states of the Frontier Strip. The Missouri River runs through the central part of South Dakota. To the east of the river lie low hills and lakes formed by glaciers. Fertile farm country covers the area. To the west of the river the land consists of deep canyons and rolling plains.