The Cheyenne River Indian Reservation is located in South Dakota and is home to the Cheyenne River Sioux Tribe. Established in 1889, the reservation covers over 4,200 square miles and is one of the largest reservations in the United States. It is situated in the central part of the state and includes parts of Dewey and Ziebach counties. The reservation's landscape features rolling hills, rivers, and grasslands, providing a habitat for various wildlife. The tribe focuses on preserving its culture and traditions while also promoting economic development through initiatives like tourism and agriculture. The Cheyenne River Sioux Tribe plays a vital role in the community's governance and social services.