New Mexico’s White Sands National Park may not be as famous as the Grand Canyon or Yellowstone, but it probably should be.
Perhaps nowhere in the Americas is there a brighter window into the lives of the region’s early inhabitants than the gypsum dunes, full of prehistoric revelations that will change our understanding of human history.
Just two years after White Sands became a national park in 2019, the discovery of fossilized human footprints became public, making this 275-square-mile desert a world center of archeology.
Radiocarbon dating of adjacent plant seed layers revealed 61 human remains pressed into the mud some 21,000 to 23,000 years ago, shocking a long-debated theory about when prehistoric people first arrived in the Americas.
Until then, the general consensus was that humans arrived in what is now North America from Asia about 13,000 to 16,000 years ago via Beringia, a now-submerged land bridge that once connected the two continents.
The White Sands discovery dramatically pushes back the timeline, suggesting that humans were on the continent during the last glacial maximum between 19,000 and 26,000 years ago, when two giant ice sheets covered the northern third of North America.
Exactly how the people arrived is still a matter of debate, with some scientists in recent years claiming that they sailed around the edge of Asia in small boats, also known as the littoral migration theory.
These tracks also provided evidence that has potentially huge implications for understanding humans’ relationships with the Great Ice Age’s most iconic megafauna, from the Columbian mammoth (a less-furred relative of the woolly family) to the saber-toothed cat.
But without the persistence of one person, this discovery might never have come to light. White Sands general resource manager David Bastos discovered what he believed to be ancient human footprints in 2009, carved in outline along the shores of long-dry Lake Otero across a field of sand dunes.
Scattered near mammoth tracks, whose outlines had all the outlines of human feet, he, then a biologist with the National Park Service, had a hard time convincing himself, much less swaying other researchers, that the tracks might date from the same era.
“When you look at it, you’re like, ‘That’s impossible. Is it?'” Bastos told CNN’s Erica Hill.
“People wanted to see pictures and said it was most likely not a human footprint, it was probably a camel slipping in the mud and making long, thin tracks. That kept happening, but I left it alone.”
But that didn’t last long, and a year later, new footprints were discovered next to the giant railroad tracks, prompting Bastos to seek a second opinion.
Again, his arguments fell on deaf ears. He was told that while the footprints may have been human in origin, it is impossible to tell for sure whether they were made a year, 100 years or even thousands of years after the mammoth footprints.
But Bastos’ confidence was growing, and he was ultimately rewarded with a smoking gun discovery in January 2016. It featured mammoth footprints directly above human footprints, the clearest suggestion yet that the two species existed at the same time.
The theory has been circulating since the 1960s that humans hunted giant animals to extinction shortly after they arrived on North American shores, but the overlapping footprints suggest that humans coexisted with animals for 10,000 years before humans went extinct, suggesting that even if humans were hunting megafauna, the practice was at least temporarily sustainable.
As researchers from around the world flew to New Mexico to see the discovery firsthand, the biologists’ phones kept ringing. However, before anyone could take a proper look, the railroad tracks were washed away by a massive flood.
Bastos consoled himself by studying the footprints of nearby giant animals, eventually coming across the giant bean-shaped outline left by the Harlanzi sloth, an early relative of modern sloths, armadillos, and anteaters, which could stand up to 10 feet tall and weigh more than a ton when fully grown.
As he was busy brushing away the sediment, fellow researcher Matthew Bennett, an expert on ancient footprints at Bournemouth University in the UK, shouted excitedly from a few feet away. Bastos ran over to peer at the fossilized human footprints among the sloth tracks.
“There is certainly evidence that they were there at the same time,” Bastos recalled.
Some archaeologists initially disputed the age of the footprints, arguing that the aquatic plants used for dating may have absorbed carbon from dissolved atoms in the water rather than from the air, potentially making the footprints appear older than they actually are.
They called for independent estimates using other dating methods, which Bennett and Bastos responded to as part of a research paper they published in collaboration with the U.S. Geological Survey in 2023. In it, they presented two new lines of evidence: radiocarbon dating of coniferous pollen and analysis of quartz grains, to “resolve” the dating controversy and reconfirm their original findings.
Since then, the discoveries have multiplied, and each new discovery puts a new brush stroke on the picture of a time when humans walked side by side with giants across a mix of grasslands and wetlands, rather than the 4.5 billion tons of sand that rolls up into 60-foot-tall dunes in today’s parks.
One track, more than 1.5 kilometers (about a mile) long, told the story of an adult woman carrying and sometimes dropping a small child on a nerve-wracking journey across muddy plains inhabited by a variety of predators, including dire wolves.
The story, detailed in a 2020 Quaternary Science Review study co-authored by Bennett and Bastos, among others, was one of many collected from White Sands over the past decade, from children playfully splashing in water that collected in the footprints of a giant sloth to a group using an early form of a travois, a type of wheelbarrow.
“The great thing about looking at footprints is that they look like movie clips in your head,” Bastos added. “It’s easy to gloss over. They were slipping, they were walking backwards, they were turning. You see all these amazing stories.”
Each new story of prehistoric people that Bastos unearths comes with a sense of déjà vu. As Bastos continued to learn about the first peoples of the Americas, he became increasingly aware of how little humans had changed over the millennia.
“The most incredible thing, I think it was expected, but we forget, is that we’re always the same,” he explained.
“You see children jumping in puddles, parents caring for their children, and going out and hunting for their families. Some stories never change…Deep down in all of us, it’s the same, and it seems like it’s always been that way.”
Bastos said new footprint fossils are discovered almost every day, and it’s perhaps ironic that White Sands has less foot traffic than many of the nation’s 63 national parks.
The Great Smoky Mountains in Tennessee and North Carolina lead the way with more than 11.5 million recreational visitors in 2025, while White Sands ranks 35th with about 659,000 visitors, according to data compiled by the National Park Service.
Bringing modern humans closer to the footprints of the region’s prehistoric inhabitants could help push such numbers up. The fossilized track is currently closed to the public to minimize the risk of damage to the site, but from 2024 various human footprints will be on display in a specialized exhibit at the White Sands Visitor Center.
Meanwhile, new waves of visitors leave new traces on the bright white sand, each footprint telling a new and sometimes very old story.
“At first, it looks like just a sand dune,” Bastos said. “But if you look a little deeper, there are always more stories.”
