1. Geologic map of the Custer quadrangle, Breckenridge and Hardin counties, Kentucky [cartographic material] Yale Public content 1977. 2012-06-04T14:22:00Z. 2012-06-13T15:03:32Z. Amos, Dewey Harold, 1925-. U.S. Geological Survey. English. Public. Kentucky, Breckinridge County, Hardin County, and U.S.