[1] The Bone Cave "contained one of the most important middle Pleistocene (Irvingtonian, approximately 750,000 years ago) fossil deposits in North America".
[2] The fossils in the cave were investigated by noted 19th-century paleontologists Edward Drinker Cope, Henry C. Mercer, and Charles M. Wheatley.
The tract containing the cave became part of the Valley Forge National Historical Park in 1978.
[4] Many fossils of prehistoric fauna are known from the site, including Ice Age taxa such as the saber-toothed cat, mastodon, short-faced bear, American cheetah, and Wheatley's ground sloth.
[8][9] Some of the species during the Irvingtonian present at Port Kennedy such as the saber-toothed cat and short-faced bear came from smaller forms of their respective genera, with sizes increasing during the Rancholabrean.