In January 2020, Jeff Pigati and Kathleen Springer, both research geologists at the U.S. Geological Survey, went to New Mexico’s Tularosa Basin at White Sands National Park to see about some footprints. These weren’t just any footprints; the fossilized tracks represent the oldest human footprints in North America. What’s more, Tularosa Basin, about 20,000 years ago, was in the midst of what’s known as the Last Glacial Maximum (LGM). During this chilly, final part of the Pleistocene Era, the global sea level was about 400 feet lower and glaciers covered 25 percent of Earth’s land. Their mission was to find out just how old these footprints were using different dating techniques of biological markers around them.
