Dr. John Speth (University of Michigan, Ann Arbor), who also excavates at White Sands, used to half-joke that the people here during the glaciation must have made all of their tools out of ice. He was confident North America was inhabited for longer than it was then believed (~13,000 years). But aside from the coastal sites that would now be underwater (sea level rose as the glaciers melted), all the inland tools appear to have melted away.

OK. Assume that the evidence is strong and true. That still doesn't mean that there's been continuous habitation. It could be evidence of a failed colonization followed by crickets.

This is one of those theories that may not have a lot of strong evidence, but I can't help but believe is true. I expect there were humans here 20, 30, 50k years ago. That's just what humans do.