Allegheny National Forest Geological Survey Map, State of Pennsylvania, 1987

Allegheny National Forest Geological Survey Map, State of Pennsylvania, 1987, Box: 80, Item: 32. Institute for the History of Technology and Industrial Archaeology Records, A&M 3936. West Virginia and Regional History Center. https://archives.lib.wvu.edu/repositories/2/archival_objects/155754 Accessed November 22, 2024.