The Cimarron River (Pawnee: Káʾit iriírakiicuhat ) extends 698 miles (1,123 km) across New Mexico, Oklahoma, Colorado, and Kansas. The headwaters flow from Johnson Mesa west of Folsom in northeastern New Mexico. Much of the river's length lies in Oklahoma, where it either borders or passes through eleven counties. There are no major cities along its route.The river enters the Oklahoma Panhandle near Kenton, crosses the southeastern corner of Colorado into Kansas, re-enters the Oklahoma Panhandle, re-enters Kansas, and finally returns to Oklahoma where it joins the Arkansas River at Keystone Reservoir west of Tulsa, Oklahoma, its only impoundment.