TWIN FALLS, Idaho (KMVT) The Cooper’s Ferry dig site is located on public land administered by the Bureau of Land Management Cottonwood Field Office.
Coeur d' Alene District Archaeologist David Sisson (Image Credit: Bureau of Land Management, flickr)
The BLM has been partnering with the Oregon State University on the archaeological excavation site.
Stone tools and other artifacts found at the site date back more than 16,000 years ago, and offer new information on how and when the first people came to the Americas. An accounting of the new evidence obtained at Cooper’s Ferry and it’s implication has been published in a=”https://science.sciencemag.org/content/365/6456/891”>Science.
David Sisson, Coeur d' Alene District Archaeologist stationed at the BLM Cottonwood Field Office and co-author of the study published in a=”https://science.sciencemag.org/content/365/6456/891”>Science. He’s worked closely with the study lead and Oregon State Professor Loren Davis.
Sisson said what was discovered at the excavation site was completely unexpected to him.
“The site is kind of nice, it’s almost like a layer cake,” Sisson said.
In that layer cake, Sisson said artifacts and tools indicate human activity occurred in the area much earlier than previously thought.
“Through the last winter, we continued to send in samples for radiocarbon dating that was below the dates of 14,000,” Sisson said.
"Those dates started roll in through the winter and they started to roll in close to 15,000, and we were in shock. We’d like to say this is what we expected but we didn’t.”
Sisson said among some of these things found at Cooper’s Ferry dating back more than 14,000 years ago include remnants of purposeful fires, called fire hearths, and a fragment of what was determined to be a horse tooth.
“Basically folks we’re hunting at a time when we had mammoths, and short-faced bears, larger bisons, and there were horses, foxes, everything you would associated with an Arctic environment.” Sisson said. “Here was our first firm proof that people we’re out here hunting these creatures.”
Near the bottom of the site, Sisson said they didn’t have any datable material but they still had artifacts below the 15,000 year old dates.
“Loren had been working with Oxford radiocarbon lab who do some of the best dating in the world,” Sisson said. “They did a statistical projection for the bottom part 15,200 to 16,500 range. Once again not expected.”
With radiocarbon dating Sisson said the site at Cooper’s Ferry is the oldest is North and South America, and that the material discovered at the very lowest levels of the sites is similar to material excavated in Japan.
“Those dates there range are 13,000 to 16,000, which is the same date range we have for the lower part of Cooper’s Ferry,” he said. “Again, it was exciting because they were of very good match for that.”
The discoveries at Cooper’s Ferry fly in the face of a more traditional “Clovis-first” hypothesis of the people who first entered the Americas.
The theory contends the Clovis culture to be the first to settle the Americas, and that the Clovis culture crossed into North America on foots by traveling across a land bridge that connected Siberia to Alaska close to 14,000 years ago when the ice sheets melted enough to allow land.
The results at Cooper’s Ferry date back before that, indicating people were already here and support a counter hypothesis of initial human migration into the Americas that occurred through a Pacific coastal route. It’s a theory that Sisson said has caused some controversy among the archaeological community before. Jim Woods, an archaeologist and former professor at the College of Southern Idaho, Twin Falls said the “Clovis-First” theory is what he learned in school but that he finds the evidence discovered at Cooper’s Ferry convincing.
“In my mind, and I’m very conservative archaeologist when it comes to dating this stuff,” Wood said. “In my mind. this site at Cooper’s Ferry is one of the first that’s really convincing that pre-dates the Clovis.”
Woods, who was enjoying the day on the Salmon River at the time of the interview, said he read the findings finds the hypothesis of initial human migration to the Americas via a Pacific coastal route intriguing.
“More of an intriguing thought than the date and everything, is the first people to come here from Asia, the first people from Asia to get here is through a coastal route,” Woods said. “The coast of glacier is no coast, it’s just ice and water and so the only way to get here is by boat and that’s what’s these researchers are proposing.”
Woods said the archaeologist at Cooper's Ferry are not the first to introduce this theory but they're the first to have good dates on it.