The result is, to my mind, the game of science at its best. Remains in a Pennsylvania site are 13 to 20,000 years old. They include two human bones whose age seems to be 12 to 14 thousand years. But skeptics find ways to question the carbon dating. But they might've been dumped there by rising water.
Similar doubts cloud similar findings in Chile.
The most notorious find of all is a recent one in Brazil. An arrangement of charcoal could be a campsite. It gives carbon dates over 30,000 years old. The pervasive problem is the lack of a corpus delicti. Until we find human remains, it's easy to be skeptical.