River, southwestern U.S. Rising in northeastern New Mexico it flows about 500 mi (800 km) to enter the Arkansas River near Tulsa , Okla.
Traversing the northern Oklahoma Panhandle, southeastern Colorado, and southwestern Kansas, the riverbed in this area is often dry and is known as the Dry Cimarron. The Santa Fe Trail crossed its valley for 100 mi (160 km), and travelers knew the Oklahoma Panhandle as the "Cimarron Cutoff."