Elevation rises as you go north in the valley to Poncha Pass, used now by U.S. Highway 285 and historically by the narrow gauge tracks of the Denver and Rio Grande Railroad. Otto Mears, then of Saguache, built and operated an historic toll road over Poncha Pass at the north end of the valley into the San Luis Valley during Colorado's 19th century mining era when the valley was the gateway to the San Juan and Gunnison country and the Ute agency was in the mountains west of Saguache.