...the Meadowcroft Rockshelter located near Avella in Washington County, in southwestern Pennsylvania, United States, dated to sixteen thousand years BP.

These discoveries have raised doubts about the "Clovis First" theory, and have led to alternative proposals for the routes of colonization and the diffusion of culture through the continent, in a heated dispute that has not been solved.

Remains of a basket dating to at least 10,900 BCE have been found at the so-called Meadowcroft rock shelter in present Pennsylvania.

The area around Meadowcroft Rockshelter, a site in southwestern Pennsylvania intermittently occupied for thousands of years (possibly as early as 17,000) is used heavily from 2000.