Regional History: Pennsylvania
- Historical Maps of Pennsylvania
- Maps of Pennsylvania from the 16th century to the present.
- http://www.mapsofpa.com/
- Exploration. Maps. Pennsylvania. Regional History.
- LIBERTY: The Jersey Central Lines Today
- Well-researched site with old and new photos of the remains of the Central New Jersey Railroad in Pennsylvania.
- http://www.freewebs.com/jerseycentrallines/
- Exploration. Pennsylvania. Railroads. Regional History. Urban Sites.
- Nepaview: Old Railroads of Northeastern Pennsylvania
- The site's author has walked extensive sections of the Erie, O&W, CNJ, and D&H railroad right-of-ways in Northeastern PA and has documented his discoveries with photos. An excellent, detailed view of the current state of these abandonments.
- http://www.nepaview.piczo.com/
- Abandonments. Exploration. Maps. Mines. Pennsylvania. Railroads. Regional History. Trails.
- The Underground Miners Website
- The official page for coal mine research and exploration in Northeastern Pennsylvania
- http://undergroundminers.com/
- Exploration. Mines. Pennsylvania. Regional History.