MINNEAPOLIS – What appear to be crude stone tools may provide evidence that people lived in Minnesota 13,000 to 15,000 years ago, which if confirmed would make them among the oldest human artifacts ever found in North America, archaeologists said Friday.
Archaeologists in the northern Minnesota town of Walker dug up the items, which appear to be beveled scrapers, choppers, a crude knife and several flakes that could have been used for cutting, said Colleen Wells, field director for the Leech Lake Heritage Sites Program.
"They don't look like much," Wells acknowledged. "They don't look pretty."
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Several archaeological experts who weren't involved with the dig expressed a healthy dose of skepticism, but they acknowledged they were also intrigued.
Wells and other archaeologists discovered around 50 objects this past year while investigating a route for a planned road that would serve a major community development project in Walker. The items were found beneath a layer of glacial deposits that had been covered by windblown deposits.
Based on what's known about the geology of the area, they believe the objects are between 13,000 and 15,000 years old.
"The finding is intriguing but it really needs to have its precise age nailed down and more needs to be known of the artifacts," said David Meltzer, an archaeologist at Southern Methodist University in Dallas.
Much more research needs to be done to allow firm conclusions, Wells and her colleagues acknowledged.
"It's bound to be controversial," said Matt Mattson, another archaeologist on the project.
Not only do the age of the items and the soil in which they were found need to be confirmed, it must also be determined whether the objects are really human-made artifacts or merely rocks that were chipped in interesting ways by glaciers during the Ice Age. And it's not yet certain if the items were left at the site by humans, or carried there by glaciers or flowing water.
Other researchers have found that that part of Minnesota apparently was something of an "oasis" around 13,000 years ago, an area free of ice cover with shifting glaciers on most sides but with an access route to the southeast, Mattson said.
Tom Dillehay, chairman of the anthropology department at Vanderbilt University in Nashville, Tenn., was intrigued by the edge he saw on a photo of one of the objects found in Walker, saying it could have been chipped by a human.
"It's probably worth protecting the site and going back in and more systematically excavating with the geologists and other disciplines to see if it's a real site," he said.
Pat Everson, head of archaeology for the Minnesota Historical Society, said she hadn't been to the site or seen the artifacts personally, but she'd read the reports, knows the archaeologists involved and considers them "perfectly credible." Still, she counted herself among the skeptics.
"It's an extraordinary claim and it requires some extraordinary evidence," Everson said. "But it's certainly worth pursuing."
Several experts agreed it is possible people were in Minnesota that long ago.
"It seems to be there is an increasing body of science that there were stone stools and people here in that time period in North America," said Dan Rogers, chairman of the anthropology department at the National Museum of Natural History at the Smithsonian Institution in Washington.
The long-accepted theory was that people first arrived in the Western Hemisphere 11,200 years ago — corresponding with the age of arrowheads found in the 1930s near Clovis, N.M. — via a land bridge from Asia over what is now the Bering Strait.
But a consensus is emerging that some humans arrived thousands of years earlier, even if scientists disagree on just how much earlier. And several agreed that if the Minnesota objects do turn out to be 13,000- to 15,000-year-old tools, they'd be among the oldest human artifacts ever found in North America.
That's why the local archaeologists are hoping to get back into the site after this winter, and hope to work out a way with the city of Walker to preserve it for sometime in the future when more advanced testing methods might be available.
"Once it's gone it's gone," Mattson said. "We're looking at absolutely irreplaceable links in human history here. Once it's gone there's no retrieving it."