Ancient footprints could be oldest traces of humans in the Americas

Human footprints from an ancient lakeshore in what is now New Mexico seem to be between 21,000 and 23,000 years old. If the dating is accurate, the prints represent the earliest unequivocal evidence of human occupation anywhere in the Americas. The footprints contribute to ongoing debate about whether human settlers from Siberia skirted down the Pacific coast of the Americas or waited until ice-age glaciers retreated from inland routes.