Standing Rock Indian Reservation

The Standing Rock Indian Reservation is a Lakota, Yanktonai and Dakota Indian reservation in North Dakota and South Dakota in the United States. The sixth-largest reservation in land area in the United States, it comprises all of Sioux County, North Dakota, and all of Corson County, South Dakota, plus slivers of northern Dewey and Ziebach counties in South Dakota, along their northern county lines at Highway 20.