Researchers have announced evidence suggesting that humans lived at the Rimrock Draw site in the mountains of Oregon approximately 18,250 years ago — thousands of years before the date previously believed to represent the arrival of the first inhabitants of North America.
The findings indicate that the site could become one of the oldest known sites of human settlement in North America, dating back to nearly 4 times the age of the Great Pyramid in Egypt — a revelation that may prompt scientists to reconsider conventional theories about how and when humans first reached the continent.
The long-held theory that the first humans entered North America around 13,000 years ago via an ice-free land corridor between Asia and America has dominated the field, but this discovery adds to a growing body of evidence suggesting humans may have arrived far earlier, possibly via coastal routes along the Pacific Ocean before inland passages opened.
During excavations, researchers from the University of Oregon unearthed 2 finely crafted stone tools made of orange agate — a form of quartz — buried beneath a layer of volcanic ash produced by an eruption of Mount St. Helens more than 15,000 years ago.
Radiocarbon analysis of the remains of extinct animals found near the tools — including camels and ancient bison — yielded an estimated age of approximately 18,250 years, indicating that the site was used by humans far earlier than previously known.
Among the more striking pieces of evidence, 1 of the stone tools bore traces believed to be bison blood, suggesting it was used to butcher or process the animal before being buried within the site.
Archaeologist Patrick O'Grady of the University of Oregon, who oversees research at the site, said the discovery of the ancient volcanic ash layer was unexpected, but that the dating results for the animal remains and stone tools made the find even more exciting, as they provided evidence of human presence dating back more than 18,000 years.
Despite the significance of the findings, they have not yet undergone peer review by independent researchers, so scientists are still treating them with caution. However, their confirmation could bring about a major change in the timeline of human migration to the Americas, according to a report by the British newspaper Daily Mail.
The researchers also believe the discovery aligns with the oral accounts of some indigenous tribes in the region, which speak of ancient geological events such as the Missoula floods and of human interaction with large animals that lived during the end of the Ice Age.
The significance of Oregon's ancient past is not confined to Rimrock Draw alone. Other discoveries in the state have revealed an advanced level of skill among early North Americans. Scientists found pieces of animal hides stitched together dating back approximately 12,000 years, indicating that humans of that era possessed sophisticated techniques for making clothing and tools.
These discoveries encompassed around 55 artefacts made from 15 different types of plant and animal materials, including remains believed to have been part of clothing or footwear, as well as tools such as baskets and wooden traps.
Together, these artefacts paint a different picture of Ice Age humans: rather than mere hunters and gatherers, the evidence suggests they were capable of innovation and adaptation, using available resources in advanced ways thousands of years before the emergence of the first civilisations.