1. Geologic map of the Crested Butte quadrangle, Gunnison County, Colorado [cartographic material] Yale Public content 1986. 2002-06-01T04:00:00Z. 2012-07-05T13:09:38Z. Geological Survey (U.S.). The Survey ; For sale by Branch of Distribution, U.S. Geological Survey. English. Public. Colorado and Gunnison County.