1. Geologic map of the Black Hawk quadrangle, Gilpin, Jefferson, and Clear Creek counties, Colorado [cartographic material] Yale Public content 1976. 2012-05-01T18:24:38Z. 2012-05-09T14:05:14Z. Taylor, Richard B. (Richard Bartlett). The Survey. English. Public. Colorado, Gilpin County, Jefferson County, and Clear Creek County.