After descending from Monarch Pass, the highway enters the Arkansas River Valley near the town of Salida. The headwaters of the Arkansas are about north near Leadville, in Climax. The Arkansas is the second-longest tributary to the Mississippi-Missouri River system. U.S. 50 closely follows the Arkansas River from Salida to Kansas. East of Salida, the highway enters a deep canyon, dubbed Bighorn Sheep Canyon. There are several small communities in the canyon including Howard, Coaldale and Cotopaxi. The major industries in the canyon are fishing and river rafting.