Archaeologica.org

In 1973, Dr. James Adovasio, then at the University of Pittsburgh, began excavating the Meadowcroft Rockshelter.

Adovasio and his crew excavated layer after layer and eventually found stone tools and evidence of fire pits. In places, the excavations went down 10 to 15 feet.

The site has produced 20,000 human artifacts, 956,000 animal bones and 1.4 million plant remains — the largest collection of plant and animal remains in a single place in North America. They include man-made objects of stone, animal bones and wood, remains of 149 animal species, and seeds, fruits, pollen, wood and charcoal. Evidence has been found of deer, elk, turkey, grouse, nuts, berries, corn, squash and freshwater mussels.