Subscribe to Archaeology

Ghost Tracks of White Sands

Scientists are uncovering fossilized footprints in the New Mexico desert that show how humans and Ice Age animals shared the landscape

November/December 2021

Whitesands Trackways DunesThe sun shines nearly 300 days a year over southern New Mexico’s Tularosa Basin, where bright white sand ripples across the desert. Here, in White Sands National Park, the world’s largest gypsum dunes abut the dried-up bed of prehistoric Lake Otero, which once covered 1,600 square miles. In the summer, park temperatures can soar to 110°F, and the intense sunlight stings the eyes. It was one of those hot but slightly hazy days in May 2021 when Bonnie Leno and Kim Charlie, sisters from Acoma Pueblo, about 175 miles north, found the fossilized tracks of a giant ground sloth and two humans, all of whom lived at least 10,000 years ago, at the close of the Pleistocene Epoch.


Leno and Charlie didn’t expect to uncover evidence of ancient history at the park, but there they were, the kidney-shaped footprints of a 10-foot-tall, 2,000-pound long-extinct mammal and the imprints of human toes—the marks of two species that coexisted thousands of years ago. “I was down on the ground, brushing everything off,” says Leno, recalling the adult human footprint she found not far below the surface. “I was ecstatic.” Just inches away, she spotted the giant sloth track. “There were a lot of prints in that area,” says Charlie, who uncovered the tiny footprint of a child nearby.


Charlie is a member of the Acoma Tribal Historic Preservation Office (THPO) board and participates in a consultation program with the National Park Service. Any time park employees conduct studies that might affect a Native cultural site, pueblos and tribes affiliated with that site are asked to consult on the research and preservation. Acoma is one of six Native groups currently studying and protecting the park’s prehistoric trackways, says David Bustos, White Sands’ resource program manager. He invited Charlie to accompany scientists and park staff on one of the first field trips to the park since the pandemic began in 2020. She in turn asked Leno, an Acoma cultural monitor who works with the THPO to study and assess archaeological sites in culturally sensitive areas. It’s a role that the sisters say is akin to retracing their ancestral footsteps.


Whitesands Trackways Leno CharlieWhite Sands has the world’s largest collection of fossilized Ice Age footprints, numbering in the hundreds of thousands. For several years, a team of archaeologists, geographers, geologists, environmental scientists, and tribal members has worked to find and analyze as many prints as possible. No one knows who the early human trackmakers were or whether they were genetically related to Native groups in the region today, but recent findings suggest people walked through these lands far earlier than scientists commonly thought. In 2019, researchers found human tracks amid sediment layers containing seeds from an aquatic plant that grew around the ancient lake. The discovery presented a rare opportunity—the scientists could radiocarbon date the seeds to derive an approximate age of the footprints. The results confirmed the presence of humans there between 23,000 and 21,000 years ago, at a time when much of modern-day North America was under ice. That discovery revived longstanding questions about how and when people first inhabited the continent. If the dates are correct, they would disprove a commonly held theory that humans arrived thousands of years later, toward the end of the Ice Age.




Recent Issues