The Folsom site in New Mexico established the antiquity of humans in North America as at between 8000 and 9000 BC or Late Pleistocene (the Pleistocene ended about 10,000 years ago) and the evidence was unequivical because a projectile point was found embedded in the matrix between two ribs of a bison dating to this time period. Previously it had been thought that mankind in North America only dated back about 3000 years.