Arrival· Where Sapiens lives
The Americas
22 ka
People are in North America while the ice sheets are still at their greatest extent.
What the evidence shows
The footprints at White Sands are not dated in themselves; the layers around them are. Seeds above and below give calibrated radiocarbon ages between 23,000 and 21,000 years, which brackets the prints rather than estimating them. That places people in North America at the height of the last glacial maximum, when the ice sheets stood at their greatest extent. It also stretches by several thousand years the period during which humans and Pleistocene megafauna shared the same ground.
Dating & uncertainty
Footprints do not lie about presence, only about date. Radiocarbon on aquatic seeds was challenged for old-carbon effects; independent dating of terrestrial pollen and of quartz grains has since supported the age.
Sources
- Bennett et al. (2021), Science · Evidence of humans in North America during the Last Glacial Maximum
- Pigati et al. (2023), Science · Independent age estimates resolve the controversy of ancient human footprints at White Sands
- Holliday et al. (2025), Science Advances · Paleolake geochronology supports Last Glacial Maximum (LGM) age for human tracks at White Sands, New Mexico