One of the most important archaeological discoveries of the last century, which rocked the field of archaeology and fundamentally shifted our collective knowledge of human occupation in the Americas.On a warm winter day in 2005, while mending fences in the backcountry of White Sands National Park, David F. Bustos, the park’s biologist turned resource-program manager, spotted his first Ice Age human footprint. He initially ignored it as a print made from a modern co...