Ancestor Tracks
- Explore county atlases of Pennsylvania Township Warrantee Maps. News, maps and history.
- http://ancestortracks.com/

Mapsite: Pennsylvania Maps
- Collection of State and major city area maps. Features detailed maps of Philadelphia, Pittsburgh, Harrisburg, Allentown and other major cities.
- http://www.pennsylvania-mapsite.com/

Environmental Protection Agency - Pennsylvania
- "Surf Your Watershed"
- http://cfpub.epa.gov/surf/state.cfm?statepostal=PA

Pennsylvania Maps
- The Perry-Castañeda Library Map Collection.
- http://www.lib.utexas.edu/maps/pennsylvania.html

Historical Maps of Pennsylvania
- Twelve maps from the 1700s, 1800s.
- http://lancaster.about.com/library/ency/pages/blmap-index.htm

Pennsylvania Spatial Data Access
- Pennsylvania's official geospatial information clearinghouse and the Commonwealth's node on the National Spatial Data Infrastructure (NSDI).
- http://www.pasda.psu.edu/

Color Landform Atlas: Pennsylvania
- The Johns Hopkins University hosts this map collection of Pennsylvania.
- http://fermi.jhuapl.edu/states/pa_0.html