Photo of a waterfall in Delaware Water Gap state park in Pennsylvania.

Pennsylvania Earth Science Quick Facts

Page snapshot: Pennsylvania State Geologic MapFossil; 3D modelsRock; Mineral; GemHighest and Lowest Elevations; Places to Visit; and Additional Resources.

Image above: Fulmer Falls in the Delaware Water Gap National Recreation Area in Bushkill, Pennsylvania. Here, Dingmans Creek (a tributary of the Delaware River) cuts through the local bedrock of tilted Paleozoic strata. Photo by Jeff Moore (Flickr; Creative Commons Attribution-NonCommercial 2.0 Generic license; image cropped and resized).

Geologic Map of Pennsylvania


Geologic map of Pennsylvania.

Geologic map of Pennsylvania showing maximum ages of mappable units. Image by Kiera D. Crowley for the Earth@Home project developed using QGIS and USGS data (public domain) from Fenneman and Johnson (1946) and Horton et al. (2017).

Pennsylvania State Fossil: Trilobite

In 1988, Pennsylvania officially named its state fossil as the trilobite Eldredgeops rana (="Phacops rana") after it was lobbied for by an elementary school science class. The species is named after its large eyes ("rana" is Latin for frog), which were composed of many individual lenses. 


Photo of a fossil specimen of the trilobite Eldredgeops rana from New York.

Fossil specimen of the trilobite Eldredgeops rana from the Middle Devonian Ludlowville Formation of Genesee County, New York (PRI 70712). This species of trilobite was geographically widespread in the Devonian, including in the state of Pennsylvania where it is the state fossil. 


Learn about the Devonian trilobite Eldredgeops rana (formerly Phacops rana) from Central New York with Dr. Carlton Brett (University of Cincinnati).

3D Models of fossils from Pennsylvania


Fossil frond of the fern (pteridosperm; not assigned to order) Eremopteris zamioides from Pennsylvanian Llewellyn Formation of Sullivan County, Pennsylvania. Specimen is on display at the Museum of the Earth, Ithaca, New York. Length of specimen is approximately 11 cm. Model by Emily Hauf.

Fossil specimen of the trilobite Wanneria walcottana from the Cambrian Kinzers Formation of Lancaster County, Pennsylvania (PRI 76846). Specimen is from the research collections of the Paleontological Research Institution, Ithaca, New York. Trilobite is approximately 12.5 cm in length. Model by Emily Hauf.

Fossil specimen of a stem base of the horsetail (Equisetophytes) Calamites suckowi from the Pennsylvanian of Pennsylvania (PRI 50479). Note the characteristic nodes (horizontal lines) and internodal ribs (vertical lines). Specimen is on display at the Museum of the Earth, Ithaca, New York. Length of fossil is approximately 21.5 cm. Model by Emily Hauf.

Fossil specimen of the cone of the horsetail Palaeostachya from the Pennsylvanian of Columbia County, Pennsylvania. This is a cone produced by a large, extinct horsetail (Calamitaceae). Specimen is from the Cornell University Paleobotanical Collection (CUPC), Ithaca, New York (#1464). Length of specimen is approximately 15 cm. Model by Emily Hauf.

Pennsylvania State Rock: None

Pennsylvania does not yet have an official state rock.

Pennsylvania State Mineral: None

Pennsylvania does not yet have an official state mineral.

Pennsylvania State Gem: None

Pennsylvania does not yet have an official state gem.

Pennsylvania's Highest and Lowest Elevations


Topographic map of Pennsylvania.

Topographic map of Pennsylvania with physiographic regions and point of highest elevation identified. Topographic data are derived from the Shuttle Radar Topography Mission (SRTM GL3) Global 90m (SRTM_GL3) (Farr, T. G., and M. Kobrick, 2000, Shuttle Radar Topography Mission produces a wealth of data. Eos Trans. AGU, 81:583-583). Image by Kiera D. Crowley for the Earth@Home project.


Highest Elevation: Mount Davis

At 979 meters (3,213 feet), Mount Davis, in Forbes State Forest, is the highest point in the state of Pennsylvania.


Photo of boulder with USGS marker denoting the highpoint in the state of Pennsylvania, Mount Davis.

The boulder at the peak of Mount Davis, the highest point in the state of Pennsylvania. The USGS marker denoting its elevation is embedded in the top of the boulder. Photo by Jimmy Emerson (Flickr; Creative Commons Attribution-NonCommercial-NoDerivs 2.0 Generic license).


Lowest Elevation: Delaware River

Pennsylvania's lowest points are along the Delaware River, which exits into the Atlantic Ocean at sea level.


Photo of the Philadelphia skyline from the Delaware River.

View from the Delaware River, looking towards Philadelphia. Photo by Peter Miller (Flickr; Creative Commons Attribution-NonCommercial-NoDerivs 2.0 Generic license).

Places to Visit


Carnegie Museum of Natural History

Pittsburgh, Pennsylvania.


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Photo of the Diplodocus dinosaur statue outside of the Carnegie Museum building in Pittsburgh, Pennsylvania.

Statue of Dippy the Diplodocus dinosaur, standing guard outside the Carnegie Museum of Natural History in Pittsburgh, Pennsylvania. Photo by Wally Gobetz (Flickr; Creative Commons Attribution-NonCommercial-NoDerivs 2.0 Generic license).


Academy of Natural Sciences of Drexel University

Philadelphia, Pennsylvania.


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Photo of wall case displaying animal specimens from the collections of the Academy of Natural Sciences in Philadelphia.

Specimens on display in the entrance lobby of the Academy of Natural Sciences in Philadelphia. Photo by "daderot" (Wikimedia Commons; public domain).


Presque Isle State Park

Erie, Pennsylvania.


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Photo of the sand beach at Presque Isle State Park in Pennsylvania.

Photo by Ken Lund (Flickr; Creative Commons Attribution-ShareAlike 2.0 Generic license; image brightened and resized).

Additional resources


Simple map highlighting the different physiographic regions of the northeastern United States.