The height of the last ice age, roughly 20,000 to 26,000 years ago, is known as the “Last Glacial Maximum.”

The debate regarding whether humans entered the Americas by way of the northern route from Siberia before or after the Last Glacial Maximum, when massive sheets of ice might have blocked travel south along the Pacific Coast or west across Canada, continues.

The ancient footprints at White Sands give the answer to that question, indicating they may have arrived up to 30,000 years ago, hundreds of years before the ice age’s peak.