How Deep Is the Arkansas River?

It’s not easy to define how deep the Arkansas River is. At 1,460 miles long, the Arkansas River is the 6th largest river in the United States. It’s also the second-longest tributary in the Mississippi-Missouri River system. The Arkansas River flows through four states and is described as having three sections. Its upper portion begins in the Rocky Mountains, where it drops 10,000 feet in only 125 miles, creating a steep torrent that’s suitable for whitewater rafting. It carves a path through the Royal Gorge, a canyon that gets as deep as 1,250 ft, then widens and flattens as it travels through the rest of Colorado and into Kansas and then Oklahoma. This middle portion of the river continues into eastern Oklahoma, where the lower portion continues into Arkansas, flowing from west to east and meeting the Mississippi River near the abandoned port town of Napolean.

The Depth of the Arkansas River

That’s a lot of water to cover. With a waterway as long as the Arkansas River, we can expect its depth to vary. Parts of the river may never have been measured. Geological surveys suggest the river can be 27 feet deep or more, with areas as shallow as 3 feet. A 2022 news report noted that the river can be as deep as 50 feet.

On the lower portion of the river, water traffic is made easier by the 445-mile-long McClellan–Kerr Arkansas River Navigation System. This series of dams, reservoirs, and locks were constructed in 1963-1970 to maintain a navigation channel at a consistent 9-foot depth. That enables commercial traffic, allowing millions of tonnage to be shipped every year. It also supports recreational use, fish and wildlife conservation, reliable water supply, and management of the water level during times of drought and flood.  

Rolling on the River

Before the arrival of Europeans, many Native American communities lived near the Arkansas River. Spanish explorers were the first Europeans to see the river, though it was a French missionary who coined the name “Arkansas” (then spelled Akansa). The river was a boundary between the United States and Mexico until the Mexican-American War.

This mighty river offers opportunities for a wide range of aquatic activities all along its length. The upper portion, in particular, is known for its excellent kayaking, white water rafting, and world-class trout fishing.  

The photo featured at the top of this post is © iStock.com/Michael Dean Shelton