1. Colorado, Denver quadrangle Yale Public content 1901. 2011-05-17T17:02:36Z. 2015-10-21T14:59:19Z. Geological Survey (U.S.). The Survey. English. Public. Arapahoe County (Colo.), Denver Region (Colo.), Douglas County (Colo.), Elbert County (Colo.), and Jefferson County (Colo.).