Pennsylvania Geological Survey Library
The DCNR Bureau of Geological Survey, also known as the Pennsylvania Geological Survey, studies all aspects of the geology of Pennsylvania and makes its findings available to the public.
Published research and other materials can be accessed by appointment at the survey library in its Middletown headquarters. A description of library items and the appointment calendar can be found below.
The Pennsylvania Geological Survey maintains collections of aerial photographs dating from 1946 to 1999, which may be checked out or viewed in the library:
Agricultural and Stabilization Conservation Series (ASCS). 1946–81. Leaf on, black and white, mostly 1:20,000 scale. Complete coverage except in Philadelphia.
U.S. Geological Survey (USGS). Mostly late 1960s and 1970s. Leaf off, black and white, majority between 1:20,000 and 1:40,000 scale. Complete coverage.
National High-Altitude Photography (NHAP). Initiated in 1980 and succeeded by the NAPP program. High altitude, mostly leaf off, black and white, 1:80,000 scale. Color-infrared photography also is available at a scale of 1:58,000. Complete coverage.
National Aerial Photography Program (NAPP). Three phases—the first started in 1987, the second in 1992, and the third in 1999. First-phase prints are leaf on, mostly black and white, some color infrared. Prints from the 1990s are leaf off, black and white. All have a scale of 1:40,000. Third-phase coverage is limited to eastern and part of central Pennsylvania.
All or parts of each collection are also available online:
Historical Aerial Viewer
is an application that includes most of the aerial photographs from the ASCS series. When zoomed to a local area or region, the map shows center-point markers indicating the eras of the available photographs.
Geologic Texts, Maps, and Journals
Visitors to the library can choose from more than 20,000 geological publications, including maps, and more than 90 geological journal titles. Search for specific listings in the State Library of Pennsylvania online catalog.
The library houses a complete collection of Pennsylvania Geological Survey publications, state-related USGS and U.S. Bureau of Mines reports and maps, and selected publications from other states and countries.
Books and journals may be checked out for up to four weeks. If you prefer, local libraries can arrange for an interlibrary loan.
Thousands of photographs taken by survey geologists and staff members, dating as far back as the early 20th century, are filed in the library. These photographs are being scanned, and you can view the scanned images online at Power Library.
The USGS publishes topographic maps -- maps that show an area’s physical and cultural features at a particular time. Through the years, maps of specific areas have been updated.
In 2009, the USGS began producing topographic maps in electronic form, and in 2011, it released scans of the older printed maps of the U.S. Read more about topographic maps and how to obtain them at USGS National Geospatial Program.
The survey library houses a large collection of paper, historical topographic maps of the state. All maps can be viewed in the library but cannot be checked out.
The maps vary in scale with area covered and include the following:
- 1:24,000-scale, 7.5-minute maps
- 1:62,500-scale, 15-minute maps
- 1:50,000-scale, countywide maps
- 1:100,000-scale, 30- x 60-minute maps
- 1:250,000-scale, 1- x 2-degree maps
- 1:500,000-scale, statewide map
The library is open to the public by appointment only, Monday - Friday, from 9:00 A.M. - 12:00 P.M., and from 1:00 P.M. - 4:00 P.M. Please click on a date on the appointment calendar below to schedule your visit. If you need to cancel or modify an appointment, contact the library at 717-702-2020.