Last updated: September 24, 2025
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Valley Forge Fossil Day 2025
NPS Graphic / G. Purifoy
Celebrating Ice Age Fossils
In honor of the 16th anniversary of National Fossil Day, Valley Forge National Historical Park is celebrating the amazing Ice Age fossils of Valley Forge with a day of interactive, family-friendly activites and special programs.
Learn about mastodons, saber-toothed cats, giant ground sloths, and lots of other incredible critters that walked the ancient landscape of Valley Forge hundreds of thousands of years before George Washington and the Continental Army ever set foot here.
When: Saturday, October 11, 2025 between 10am and 4pm
Where: Visitor Center at Valley Forge
Photo by Justin Tweet, used with permission of Ted Daeschler/Academy of Natural Sciences of Drexel University.
The Port Kennedy Bone Cave (in what is now Valley Forge National Historical Park) was discovered during limestone quarrying in the 1870s and explored through the 1890s. Around 1,200 fossil specimens were removed, including fossilized bones from Ice Age (Middle Pleistocene) mammals like bears, giant sloths, American cheetahs, saber-toothed cats, mastodons, and many more!
Today, most of the fossils are in the collections of the Academy of Natural Sciences of Drexel University in Philadelphia and the American Museum of Natural History in New York.
Learn more!
License for movie screening and promotional materials provided by Criterion Pictures.
Movie Screening: Ice Age (2002)
REGISTRATION IS REQUIRED!
Please send an email to vafo_information@nps.gov to register. Include the total number of people in your group. Your confirmation email will serve as your ticket. Bring a copy with you (on your phone or printed out) and present it when you enter the theater on October 11. Screening is limited to 250 people.
10am in the Theater at Valley Forge. Short ranger talk about fossils after the movie.
Manny the mammoth, Sid the loquacious sloth, and Diego the sabre-toothed tiger go on a comical quest to return a human baby back to his father, across a world on the brink of an ice age.
Rated PG. 1 hour and 21 minute run time.
Fossil Day Science Talks
An Entrance to Former Worlds: the Cave, Landscape, and Geologic History of Valley Forge
1pm in the Theater at Valley Forge
John A Sime, PhD
Drexel University
This is a story about how five-hundred-million-year-old rocks, which formed beneath ancient seas, came to entomb five-hundred-thousand-year-old fossils, that recorded the demise of extinct land mammals.
Ancient Flora and Fauna of Valley Forge
2pm in the Theater at Valley Forge
Steve Jasinski
Harrisburg Universty of Science and Technology
Learn about the Pleistocene plants and animals that walked the ancient landscape of Valley Forge.
Finding the Lost Valley Forge Bone Cave Using Geophysical Imaging
3pm in the Theater at Valley Forge
Timothy D Bechtel PhD, PG
Senior Teaching Professor of Geoscience, Franklin & Marshall College
How was the Valley Forge Bone Cave lost, rediscovered, studied, then buried again after its initial discovery and exploration in the 1800s?
NPS Image
Be a Junior Paleontologist
11am to 3pm in the Visitor Center at Valley Forge
Pick up a copy of the Junior Paleontologist Activity Booklet in the Visitor Center at Valley Forge! Complete the activities in the booklet and show it to a ranger in the visitor center to earn a special Junior Paleontologist badge. (While supplies last!)
See Some Fossils!
11am to 3pm in the Visitor Center at Valley Forge
Meet paleontologists from the Academy of Natural Sciences of Drexel University! Explore real fossils, casts of fossils, and how these animals ended up together in what is known as the Port Kennedy Bone Cave.