1. Geologic map of parts of the Benham and Appalachia quadrangles, Harlan and Letcher counties, Kentucky [cartographic material] Yale Public content 1973. 2012-03-30T18:01:11Z. 2012-05-03T15:34:47Z. Froelich, A. J. (Albert Joseph), 1929-. U.S. Geological Survey. English. Public. Kentucky, Harlan County, and Letcher County.