CORVALLIS, Oregon – Stone tools and other artifacts unearthed from an archaeological dig in Cooper’s Ferry site in western Idaho suggest that people lived in the area 16,000 years ago. That’s more than 1,000 years earlier than scientists previously thought. The findings, published in Science at the end of last month, add weight to the hypothesis that initial human migration to the Americas followed a pacific coastal route rather than through the opening of an inland ice-free corridor.
Anthropology professor Loren Davis is the study’s lead author.
“The Cooper’s Ferry site is located along the Salmon River, which is a tributary of the larger Columbia River basin,” he said in a prepared release. “Early peoples moving south along the Pacific coast would have encountered the Columbia River as the first place below the glaciers where they could easily walk and paddle into North America. Essentially, the Columbia River corridor was the first off-ramp of a Pacific Coast migration route.”
Davis began studying Cooper’s Ferry as an archaeologist for the Bureau of Land Management in the 1990s. After joining the faculty at OSU, he partnered with BLM to bring students from Oregon State and elsewhere to a summer archaeological field school from 2009-2018.
The dates from the oldest artifacts challenge the long-held theory that early migration involved a land bridge from Siberia into North America. The ice-free corridor was believed to have opened 14,800 years ago, which is well after the date of the oldest artifacts found at Cooper’s Ferry.
“Now we have good evidence that people were in Idaho before that corridor opened,” Davis said. “This evidence leads us to conclude that early peoples moved south of the continental ice sheets along the Pacific coast.”