The Arkansas has three distinct characters in its long path through central North America. At its headwaters the Arkansas runs as a steep mountain torrent through the Rockies, dropping 4600 feet in 120 miles. At Cañon City, Colorado, it leaves the mountains and enters Royal Gorge. For most of its length through the rest of Colorado and Kansas, it is a typical prairie river, with wide shallow banks, subject to some flooding. Through Oklahoma and Arkansas, the river deepens and builds once again into a navigable body of water somewhere between Fort Smith, Arkansas and Pine Bluff, according to the season. From this point to its mouth the Arkansas sees commercial barge traffic and some passenger and recreational use.
Many nations of Native Americans lived near or along the Arkansas in its 1450-mile stretch, but the first Europeans to see the river were members of the Coronado expedition on June 29, 1541. Also in the 1540s Hernando de Soto discovered the junction of the Arkansas with the Mississippi. The name "Arkansas" was first applied by Father Jacques Marquette, who called the river Akansa in his journal of 1673.
From 1819 the Adams-Onís Treaty set the Arkansas as part of the frontier between the United States and Spanish Mexico, which it remained until the annexation of Texas and Mexican-American War in 1846. Later, the Santa Fe Trail followed the Arkansas through much of Kansas.