Maps 18 Description and travel 11 Roads 10 History 9 Geology 5 Outdoor recreation 5 Recreation areas 5 more ... Bibliography 4 Manuscript maps 4 Pennsylvania--Maps--18th century 4 Railroads 4 Real property 4 Cartography 3 Maps, Topographic 3 Atlases 2 Catalogs 2 Coal mines and mining 2 Geology, Stratigraphic 2 Harbor 2 Harbors 2 Historic sites 2 Population 2 Railroad 2 Sources 2 Statistics 2 World maps 2 Administrative and political divisions 1 Anthracite coal industry 1 Battlefields 1 Boat ramps 1 Boats and boating 1 Cartes manuscrites 1 Census districts 1 Census, 21st, 1990 1 Church records 1 Church records and registers 1 Coal 1 Counties 1 Covered bridges 1 Earthquakes 1 less ...