Standing Rock Reservation

The Standing Rock Reservation straddles the North Dakota–South Dakota line along the west bank of the Missouri River, covering about 3,570 square miles of prairie and river breaks. It is home to the Standing Rock Sioux Tribe, which includes both Lakota bands, the Hunkpapa and Sihasapa, and Dakota bands, the Yanktonai. The reservation takes its name from a sacred stone, Íŋyaŋ Woslál Háŋ, and its rights rest on the Fort Laramie Treaty of 1868. The tribal headquarters is at Fort Yates.

The Hunkpapa leader Sitting Bull lived here and was killed by agency police on the reservation in December 1890. The Oahe Dam reservoir later flooded more than 200,000 acres of Standing Rock and Cheyenne River land. In 2016 the reservation became the center of a worldwide protest movement, led by people who called themselves water protectors, against the Dakota Access Pipeline's crossing beneath Lake Oahe just upstream. The pipeline has carried oil since 2017, the Army Corps approved the crossing in May 2026, and the tribe has said it is weighing further legal action.

• Lake Oahe
  A 231-mile Missouri River reservoir across the Dakotas borders
• The Missouri River
  The longest river in North America borders
• North Dakota
  The Peace Garden State, northern plains and badlands located in
• South Dakota
  The Mount Rushmore State, plains, badlands, and Black Hills located in
• Dakota Territory
  The territory that became North and South Dakota related