1. Geologic map of the Fort Logan quadrangle, Jefferson, Denver and Arapahoe Counties, Colorado [cartographic material] Yale Public content 1978. 2012-06-06T14:07:19Z. 2012-06-13T15:04:47Z. Lindvall, Robert M. (Robert Marcus), 1916-. U.S. Geological Survey. English. Public. Colorado, Jefferson County, Denver County, and Arapahoe County.