Author
Pennsylvania. Department of Conservation and Natural Resources
Geological Survey of Pennsylvania
4
Pennsylvania. Bureau of Topographic and Geologic Survey
3
Dodge, Clifford H.
2
Faill, Rodger T.
1
McCoy, Kaycee L.
1
Miles, F.
1
Pennsylvania. Department of General Services
1
Pennsylvania. Department of Transportation. Geographic Information Division
1
Schmitt, Zachary
1
Sevon, William D.,
1
Shaulis, James R.
1