, a major tributary of the Mississippi River. From its source in the Rocky Mountains in central Colorado, the Arkansas flows generally southeastward for about 1,450 miles (2,330 km) through Colorado, Kansas, Oklahoma, and Arkansas. It enters the Mississippi River in southeastern Arkansas.

The Neosho, Canadian, Cimarron, and Verdigris are the Arkansas' chief tributaries. Cities on the river include Wichita, Kansas; Tulsa, Oklahoma; and Little Rock, Arkansas. The volume of water carried by the Arkansas varies considerably from season to season. Numerous dams throughout the drainage basin are used for flood control, electric power, and storage of irrigation water. A barge channel, 450 miles (720 km) long, is maintained from the mouth of the Arkansas to a point near Tulsa on the Verdigris River. In the mountains near Canon City, Colorado, the river has cut a spectacular canyon, Royal Gorge. .)