Study disputes age of key Monte Verde site in Chile for earliest Americans

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A study published this week in Science has challenged the age of Monte Verde, a Chilean archaeological site long treated as some of the strongest evidence for the earliest human presence in the Americas. For years, scientists pointed to evidence dating back to roughly 14,500 years ago, including footprints, wooden tools, building foundations and the remains of an ancient fire pit.

In the new analysis, researchers say the geology around Monte Verde indicates the site is much younger than previously believed. Lead co-author Claudio Latorre, of the Pontifical Catholic University of Chile, said the team’s reinterpretation of the site’s geology leads to a maximum age for the Monte Verde site of 8,200 years before present.

The researchers’ approach focused on the landscape around Monte Verde. They sampled and dated sediments from nine areas along the Chinchihuapi Creek associated with the site, then examined how the terrain changed over thousands of years. They said they uncovered a layer of volcanic ash tied to an eruption dating back to about 11,000 years ago, and that the deposits above that ash layer—where Monte Verde’s wood and artifacts were found—must therefore be younger than that volcanic event, Latorre said.

Latorre’s team also suggested that natural landscape processes could have contributed to the revised timing. They pointed to changes such as stream erosion that may have mixed older layers with newer material, potentially leading researchers to date some ancient wood as part of the Monte Verde site even if it belonged to a different period.

The findings have not settled the debate. Michael Waters of Texas A&M University, who said he had no role in either the original or new research, argued that the new study’s conclusions are not supported by the data. Waters said the paper provides “at best, a working hypothesis that is not supported by the data they presented.”

Others involved in the first excavations also disputed the new interpretation. In an email, archaeologist Tom Dillehay of Vanderbilt University, who led the site’s initial excavations, said the new reading “disregards a vast body of well-dated cultural evidence.” Dillehay pointed to artifacts that he said have been directly dated to about 14,500 years ago, including a mastodon tusk fashioned into a tool, a wooden lance and a digging stick with a burned tip.

Independent experts who were not part of the new study also questioned whether the samples and the ash layer could be used to determine a single age for Monte Verde itself. They said the geology they analyzed was not comparable to the site location and argued that there is not enough evidence the volcanic ash once covered the entire area surrounding the site. They also said the new study does not provide a sufficient explanation for the older artifact dates.

The new study’s authors responded to the criticisms by saying they sampled within, upstream and downstream of the site, and they said there is not enough evidence that the dated artifacts at Monte Verde truly reflect an age of about 14,500 years. Co-author Todd Surovell, of the University of Wyoming, said the prior dating framework does not compel the earlier conclusion.

The Monte Verde site is central to a wider scientific question about how people moved into the Americas, including timing relative to large ice sheets that covered parts of Canada. Scientists long debated whether earliest arrivals came in time for an ice-free corridor to open, whether coastal travel by boat played a role, or whether people moved through a mix of land and water routes as glaciers retreated.

Monte Verde first drew attention decades ago and became widely cited after earlier controversy. Since then, researchers have also identified other sites in North America that predate the Clovis culture, including Cooper’s Ferry in Idaho and the Debra L. Friedkin site in Texas, raising additional questions about how consistent those early chronologies are across regions.

It remains unclear how the new maximum age for Monte Verde would affect the broader human-migration story. But Surovell said a revised date could reopen discussions about which route early humans used. He said future independent analyses of other early human sites could provide additional clarity, adding that science is self-corrective—“It eventually reaches the truth,” he said.