Pittsburgh Coal Bed Resource Areas in Pennsylvania, Ohio, West Virginia, and Maryland

The base of the Pittsburgh Coal bed and its stratigraphically (non-coal)
equivalent horizon is used to subdivide Upper Pennsylvanian Series strata
into the overlying Monongahela Group and the underlying Conemaugh Group
in the Appalachian Basin coal region. This dataset depicts areas in which
Pittsburgh coal resources were calculated and was obtained largely from
published maps. Because different coal thickness criteria
were used to delineate the line denoting known resources in Ohio versus
West Virginia, an offset is observed at the State boundaries.
This dataset is a polygon coverage of counties limited to the extent of
the Pittsburgh coal bed resource areas. The file has been generalized from
detailed coverages found elsewhere in Professional Paper 1625-C.