George's Creek Coal Basin
Map of Georges Creek Coal Basin showing the location of mining properties and the areal extent of the Pittsburg ("Big Vein") and Lower Coals.
Maryland Geological Survey,
Wm. Bullock Clark, State Geologist
1903.
Mining Properties by B. S. Randolph
Geology by G. C. Martin
Typology by the Maryland Geological Survey in cooperation with the U. S. Geological Survey