Meadowcroft Rock Shelter
A local property owner discovered this site in 1955 but kept a lid on it until 1973, when University of Pittsburgh archaeologists led by James Adovasio began to excavate. They found artifacts about 3,000 years older than those at Clovis, sparking a great academic controversy.
Meadowcroft, 35 miles southwest of Pittsburgh, is now a National Historic Landmark run by the Senator John Heinz History Center in Pittsburgh, a Smithsonian affiliate. Dug from a cliff face 45 feet above Cross Creek, the rock shelter was once largely inaccessible. Now there are tours, and a stairway climbs the hillside to a 2007 building that protects the original site and areas still to be excavated. A visitor center offers exhibits. Open May through October.