Cheyenne River

The Cheyenne River (Lakota:Wakpá Wašté; "Good River"), also written Chyone, referring to the Cheyenne people who once lived there, is a tributary of the Missouri River in the U.S. states of Wyoming and South Dakota. It is approximately 295 miles (475 km) long and drains an area of 24,240 square miles (62,800 km). About 60% of the drainage basin is in South Dakota and the remainder in Wyoming.