In 1929 Ridgley Whiteman, then just a teenager, made an archeological discovery that would forever change our understanding of the first Indigenous people to land in North America. He found what would later be known as Clovis points, named after the town of Clovis, New Mexico, the site of their discovery. The fluted projectile points, dating back 13,000 years, show that ancestral Indigenous people not only lived in North America but also had the technology to hunt megafauna like woolly mammoths and large Pleistocene bison.
But now, a new study published in the journal Science Advances has uncovered stemmed projectile points that are 3,000 years older than Clovis. Researchers used radiocarbon dating on pieces of animal bone found next to the points at the Cooper's Ferry site in western Idaho. The discovery means that humans were here earlier than we thought —16,000 years ago — and already had the technology for hunting large game.
The Earliest Humans
"We've had expectations for some time that people should have been present in the Americas by around 16,000 years ago, but now we have artifactual evidence to prove it," says Loren Davis, lead study author and executive director for the Keystone Archaeological Research Fund at Oregon State University.
This is a huge finding because it's not just a few pieces found scattered about. It's the discovery of 14 stemmed points, many of them fully intact, that were made of locally available rock. "It gives us a lot of details about how early inhabitants were putting their ideas to work to make very distinctive artifacts," says Davis.
Davis has been working at the Cooper's Ferry site since 1997. He says that as his team digs deeper, each "pit feature," or separate grouping of tools, artifacts, points and bones, have been older, moving from around 13,250 to 14,000 and, most recently, 16,000 years. "The deeper we dig, the older the artifacts," he says.
The Passage to North America
The site is likely home to such a rich history largely because of the shape of the glaciers that blanketed North America at the time, says Davis. The ice sitting on modern-day Canada would have made it difficult to travel across the land and down into the lower 48 states. Instead, early Indigenous people may have traveled south along the Pacific Coast. "The first left-hand turn south of the ice would have been the Columbia River, and if you follow it upstream, you'll reach the Salmon River and the Cooper's Ferry site," says Davis.
The findings disprove the long-running theory that early North Americans made their way down into the lower 48 through a break in the glacial ice around modern-day Alberta. "The 'ice-free corridor' located around Alberta didn't open up until 13,000 years ago, so older archeological sites below the ice sheets indicate that people had to have reached the lower 48 through some other passage," says Geoffrey M. Smith, executive director of the Great Basin Paleoindian Research Unit at the University of Nevada Reno, who was not involved in the study.
Smith agrees that the evidence gathered by Davis and his team shows that much of the passage into the Americas was most likely made along the Pacific Coast. "People seemed to have been able to travel along the coast accessing habitable terrain and food sources for much of that passage," he says. Unfortunately, says Smith, most of the archeological evidence along the Pacific coast that could prove this theory has been destroyed due to rising water levels.
There's still a lot we don't know about how early peoples made their way to North America. But we're learning more and more about when they came and the technology they had upon their arrival. While we might never know the full picture, what we've already learned continues to leave Davis and his colleagues in awe. "Each time I think I couldn't be more amazed we find something new, and I have to adjust my level of excitement," he says.