1. Motor vehicle use map, Sulphur Ranger District, Arapaho National Forest, Colorado Yale Public content 2007. 2008-01-03T15:48:30Z. 2011-03-03T23:39:59Z. United States. Forest Service. U.S. Dept. of Agriculture, Forest Service. English. Public. Colorado, Arapaho National Forest, Arapaho National Forest (Colo.), and Sulphur Ranger District (Colo.).