compiled from the Survey by Richard H. Sanders, A. Dw. Smith ... [and others] Topographical map of the Blue Mountain at Port Clinton in 2 sheets / surveyed and drawn by George M. Lehman. --
Date
1881-91
Series
Report of progress (Geological Survey of Pennsylvania) ; AA Atlas Suppl. 2
edited by Joseph T. Hannibal, Cleveland Museum of Natural History, Cleveland, Ohio, Kyle C. Fredrick, California University of Pennsylvania, Department of Earth Sciences, California, Pennsylvania