A map of the Arkansas River. The river is in red.
The Arkansas River is a river in the United States. It flows southeast and is a tributary of the Mississippi River. It is about 1,469 miles (2,364 km) long. It is the sixth longest river in the United States.
The Arkansas begins in the state of Colorado. Then, it flows through the states of Kansas and Oklahoma. It flows into the Mississippi River in Arkansas. It takes its name from this state.
It has several major tributaries. These are the Canadian River, the Cimarron River, and the Salt Fork Arkansas River. It is the 6th longest river in the USA.