This digital image was produced in the Summer of 2012 by the Maryland State Archives (MSA) from the original map held by the Maryland Geological Survey (MGS). We are indebted to the staff of the MGS and MSA for helping us make this these images available.This map is Figure 5 from Otton. E.G., and Hilleary, J.T., “Maryland Strings – their Pphysical, Thermal and Chemical Characteristics”. Baltimore: Maryland Geological Survey, 1985 (Report of Investigations No. 42)