Historical Maps of Pennsylvania - Maps with descriptions and commentary from the 17th through 20th centuries. Color Landform Atlas: Pennsylvania - The Johns Hopkins University hosts this map collection of Pennsylvania. Pennsylvania Spatial Data Access - Pennsylvania's official geospatial information clearinghouse and the Commonwealth's node on the National Spatial Data Infrastructure (NSDI). Pennsylvania Maps - The Perry-Castañeda Library Map Collection. Environmental Protection Agency - Pennsylvania - "Surf Your Watershed" Ancestor Tracks - Explore county atlases of Pennsylvania Township Warrantee Maps. News, maps and history. Pennsylvania Map - Features printable maps, including detailed road maps, a relief map, and a topographical map.