The Arkansas River is a major tributary of the Mississippi River. The Arkansas generally flows to the east and southeast, and traverses the states of Colorado, Kansas, Oklahoma, and Arkansas. At 1,469 miles (2,364 km) it is the sixth longest river in the United States the second-longest tributary in the Mississippi-Missouri system, and the 45th longest river in the world. Its origin is in the Colorado Rockies in Lake County near Leadville, and its outlet is at the historic site of Napoleon, Arkansas. The Arkansas River drainage basin covers nearly 195,000 sq mi (505,000 km²).
At its headwaters the Arkansas runs as a steep mountain torrent through the Rockies in its narrow valley, dropping 4600 feet (1.4 km) in 120 miles (193 km). This section (including The Numbers, Brown's Canyon, and the Royal Gorge) sees extensive whitewater rafting in the spring and summer. Below the Royal Gorge, at Cañon City, Colorado, the Arkansas River Valley widens and flattens markedly. Just west of Pueblo, Colorado, the river enters the Great Plains. Through the rest of Colorado, through Kansas, and through northern Oklahoma to Tulsa (, it is a typical Great Plains riverway, with wide shallow banks, subject to seasonal flooding. Tributaries include the Cimarron River (flowing from northeastern New Mexico) and the Salt Fork Arkansas River. Below Tulsa, and continuing to its mouth, the river is navigable by barges and large river craft thanks to a series of dams that turn it into reservoirs. (Above Tulsa, it is navigable only by small craft such as rafts, canoes, and kayaks.)
Important cities along the Arkansas include Pueblo, Colorado; Wichita, Kansas; Tulsa, Oklahoma (as seen in the photo above); Fort Smith and Little Rock, Arkansas. (Read more...)