The Cheyenne River is a tributary of the Missouri River, located in the central part of the United States. It flows through South Dakota, primarily in the Cheyenne River Indian Reservation, which is home to the Lakota Sioux tribe. The river is approximately 300 miles long and is known for its scenic landscapes and diverse wildlife. The Cheyenne River plays a significant role in the local ecosystem and supports various recreational activities, such as fishing and kayaking. It also serves as an important water source for agriculture in the surrounding areas, contributing to the region's economy and sustainability.