Humans May Have Reached New Mexico 23,000 Years Ago
Kiona Smith, Ars
Footprints left behind in layers of clay and silt at New Mexico's White Sands National Park may be between 23,000 and 21,000 years old. That's based on radiocarbon dating of the remains of grass seeds buried in the layers of sediment above and below the tracks. If the dates are correct, the tracks are evidence that people walked beside the now-dry Lake Otero during the height of the last ice age, when kilometers of ice covered the northern half of the continent.