Superior National Forest crews were working on restoring erosion in the Boundary Waters Canoe Area Wilderness in 2003 when archaeologists discovered broken pieces of an ancient cooking vessel.
Nearly two decades later, they found funding to do radiocarbon dating on food residue found inside one of the pieces.
Such age-testing methods haven’t often been successful in the Boundary Waters area, where winds disturb the soil and frequent wildfires contaminate samples.
But this time, a lab at University of California, Irvine was able to provide rare and exciting results, revealing the age of the vessel to between 1,600 and 1,750 years, or between 272 and 422 A.D.
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“Any radiocarbon date is cool, because it gives us a point in time where people are on the landscape,” said Lee Johnson, forest archaeologist with the Superior National Forest. “That's why this site is unique. It's a point in time when someone was cooking something in that vessel that boiled over, and the residue carbonized on the pot.”
The findings indicate the long history of Native Americans using the site in the border lakes region during the summer months, for fishing and processing of wild rice.
“We’re fairly certain that there were people here, ancestral Native Americans, here on the landscape very soon after the last glaciers pulled north 10,500 or 11,000 years ago,” Johnson said.
The decorative elements on the pottery pieces are linked to a Native American group known as the Laurel people, who lived in the Upper Midwest and Canada beginning more than 2,000 years ago.
The Laurel people occupied a vast area, from Lake Superior up into Manitoba and Ontario, said David Mather, the National Register archaeologist for the Minnesota State Historic Preservation Office. They were the earliest in the area to adopt mound building and continental trade networks, Mather said.
The latest radiocarbon dating builds on previous work analyzing samples from the same site, Johnson said. In 2008, an obsidian flake leftover from someone making or sharpening a tool was discovered from the site. Archaeologists traced its origin to Bear Gulch, Idaho, indicating that trade networks extended from there to present-day Minnesota.
Researchers from Lakehead University in Thunder Bay, Ontario also identified corn and wild rice remains on ceramic pieces and in soil samples at the same site in 2010, indicating the food sources available at the time.
Johnson said the latest results reinforce that while the border lakes region of the Boundary Waters is a wilderness area, it still has a long history of human use.
“The Boundary Waters, the Superior National Forest is a landscape that's loved by a lot of people,” he said. “People were utilizing this landscape far back in time. It was a landscape that was loved then, too. So I think that's an important piece.”