New radiocarbon dating of purportedly 23,000-year-old footprints discovered in a dried lakebed in White Sands, New Mexico, has confirmed their age, reigniting controversy regarding the earliest arrival of humans in the Americas.

Several scientists have questioned the early dating of the fossil footprints, and have noted the lack of artifacts found at the location. However, the scientists behind the newly confirmed dates say the transitory nature of their location supports the idea that the makers of the 23,000-year-old footprints were likely only passing through and did not leave any objects behind.

23,000-Year-Old Human Footprints Appear 10,000 Years Too Early

For much of the 19th and early 20th centuries, archaeologists believed humans had not arrived in the Americas until as recently as 3,000-4,000 years ago. In the late 1920s, archaeological discoveries at sites like Folsom and Clovis in New Mexico pushed that date back thousands of years, with the most commonly accepted date for human arrival being extended to 13,000 years ago. This date is supported by geological history, indicating that the land bridge between Asia and North America would not have been passable 10,000 years earlier.

The situation changed in 2019 when researchers from the UK’s Bournemouth University and the U.S. National Park Service unearthed a series of undoubtedly human footprints in White Sands dated to between 21,000 and 23,000 years ago. As noted, those findings, which were published in 2021, remain highly controversial since they seem to go against a relatively well-established timeline.

“The immediate reaction in some circles of the archeological community was that the accuracy of our dating was insufficient to make the extraordinary claim that humans were present in North America during the Last Glacial Maximum,” said study author and U.S. Geological Survey USGS research geologist Jeff Pigati in a later statement.

Even Pigati and colleagues’ 2023 follow-up analysis lending support for the extremely ancient date, as well as a separate study offering evidence of 22,000-year-old transport technology in the same area, and the discovery of an alternate, ancient ice-highway route from Asia to North America still did not manage to settle the debate.

Recently, Vance Holiday, an archaeologist and geologist from the University of Arizona whose 2012 study of the White Sands area just a few yards from the location of the footprints assisted with their initial 2021 dating, returned to perform a new analysis of the footprints. Unlike previous tests that relied on seeds and pollen to date the footprints, Holliday and his team used radiocarbon dating of ancient mud in an independent lab to confirm the controversial dates.

New Soil Radiocarbon Dates Confirm Ancient Origin

Before returning for a new set of tests, Holliday enlisted the help of Jason Windingstad, a doctoral candidate in environmental sciences who worked as a consulting geoarchaeologist for previous research projects at White Sands.

During several outings in 2022 and 2023, the duo dug a new series of trenches in the dried ancient lakebeds. These efforts included collecting ancient mud samples taken from the beds of a stream where the supposedly 23,000-year-old footprints were discovered. Holliday says even more ancient evidence was likely here at one time, but millennia of wind erosion have left scarce material for his team to study.

“The wind erosion destroyed part of the story, so that part is just gone,” he explained. “The rest is buried under the world’s biggest pile of gypsum sand.”

After returning the samples to the lab, radiocarbon dating tests were performed. Like the tests of pollen and seeds, the new tests dated the soil to thousands of years before the generally accepted timeline for human arrival. Specifically, the tests showed the mud is between 20,700 and 22,400 years old. The team said these new findings support the idea that humans were walking on this beach between 21,000 and 23,000 years ago. The team notes that these recent tests were performed at independent labs.

“These wetland radiocarbon dates came from labs unaffiliated with the original 2021 study,” the team explained, “placing humans at the site squarely in the LGM (Last Glacial Maximum) and supporting an early human presence in North America.”

Controversy, Contradictions, and a Strange Feeling

In their conclusion, the researchers point out that this is the third type of material used to date the ancient footprints, and all tests were performed by different labs. As a result, the two research groups have a total of “55 consistent” radiocarbon dates.

“It’s a remarkably consistent record,” said Holliday, “You get to the point where it’s really hard to explain all this away. As I say in the paper, it would be serendipity in the extreme to have all these dates giving you a consistent picture that’s in error.”

Still, Holliday and Windingstad said critics continue to note the lack of artifacts or settlements at the scene of the supposedly 23,000-year-old footprints supporting the ancient occupation date. Although the findings of the new study did not directly address this criticism, they point out that the tracks in question “would have taken just a few seconds to walk.” Holliday also said that given the value hunter-gatherers would have likely placed on resources, “it’s not logical” they would leave behind a debris field.

“These people live by their artifacts, and they were far away from where they can get replacement material,” Holiday argues. “They’re not just randomly dropping artifacts.”

Holliday says he is always open to more information that refutes his team’s findings. However, he also says he was confident “from the outset” because of the consistent test results and the volume of data supporting the earlier occupation date.

“We have direct data from the field – and a lot of it now,” he said.

Windingstad agrees, noting that the results give him a new perspective on a site he has been visiting and helping study for years.

“It’s a strange feeling when you go out there and look at the footprints and see them in person,” he said. “You realize that it basically contradicts everything that you’ve been taught about the peopling of North America.”