A pre-historic stone tool unearthed by educators and students of the University of Oregon’s Archaeological Field School suggests that people were living in Oregon 18,000 years ago. That is far earlier than scholars previously thought, and at least 1,000 years before the Clovis culture, once seen as the oldest in the Americas.
The University of Oregon team, working with the Bureau of Land Management (BLM), announced Thursday that a blood residue analysis revealed animal proteins on a human-crafted scraper tool extracted from Rimrock Draw Rockshelter in southeastern Oregon. The animal was likely the Pleistocene species Bison antiquus, an extinct ancestor of the modern buffalo, according to a BLM news release.
The team, which has been excavating the rockshelter site near Riley since 2011, discovered the tool made from orange agate in 2012. The tool was preserved well under a layer of undisturbed ash from a Mount St. Helens eruption more than 15,000 years ago. Also found were fragments of tooth enamel from a Pleistocene camel, a species that went extinct about 13,000 years ago.
In 2015, the team found another crafted scraper under ash. Experts believe the tools with a created serrated edge were used for butchering animals and scraping hides.
The tooth enamel, the tools’ positions within the site’s stratigraphy and other data suggest that Rimrock Draw Rockshelter could be the oldest site of human occupation in North America, say experts.
Radiocarbon-dating analysis on the tooth enamel in 2018 and 2023 by Dr. Thomas W. Stafford Jr. of Stafford Research and Dr. John Southon of University of California, Irvine, dated the objects as 18,250 years old (14,900 radiocarbon years), stated the news release.
Additional testing of Ice Age camel and bison teeth fragments is taking place now, and archaeo-botanists are studying plant remains from cooking fires in the Rimrock Draw area, says the BLM.
Patrick O’Grady, director of the Rimrock Draw excavations and staff archaeologist with the university’s Museum of Natural and Cultural History, was working at the site Thursday alongside students enrolled in a six-week-long archeology field session.
“There’s a great deal of interest and people are checking in to see what’s next,” said O’Grady.
Chelsea Rose, a historical archaeologist and director of the Southern Oregon University Laboratory of Anthropology in Ashland, said two of her students are working at the site. “I wish I could be there today,” she said. “It’s just a really exciting time to be an archaeologist in Oregon.”
Rose and other experts not involved in the University of Oregon’s decades-long excavation work acknowledge that the university’s anthropology department, founded almost a century ago by Luther Cressman, has produced groundbreaking scholarship.
“They are making Oregon archaeology look good around the world,” Rose said. “They found the tool 11 years ago and took the time to have the information confirmed about this important discovery.”
The Rimrock Draw area’s geology and cave systems protected the ancient deposits, and new technology and techniques allowed the team to extract microscopic data to reveal how people lived 18,000 years ago in a land that once supported camels and bison, Rose said.
“All of that tells a compelling story that we wouldn’t have been able to tell 15 years ago,” she said. “And it confirms what Indigenous people have been telling archaeologists for years, that things are much older than believed.”
In 2008, research by UO archaeologist Dennis Jenkins revealed human occupation at Oregon’s Paisley Caves that predated Clovis by 1,000 years.
Cooper’s Ferry, another archaeological site on BLM-managed public lands in western Idaho, is thought to be the oldest known site in western North America. Evidence there suggests human occupation dating back more than 16,000 years, says the BLM.
“This is a very exciting development for the archaeological community,” Heather Ulrich, BLM Oregon/Washington Archaeology lead, said in the news release. “Thanks to the partnership with Dr. O’Grady and the university, these new dates push our archaeological knowledge of human occupation in North America even farther, perhaps the oldest yet.”
Scholarly records of the state’s early human populations began in the 1930s by the late Luther Cressman, who has been called the father of Oregon archaeology and anthropology, and is best known for finding the world’s oldest shoes in 1938 near the Fort Rock volcanic crater in Central Oregon’s Northern Great Basin.
His leadership through the 1960s established records of the state’s ancient human history and occupation by Native peoples, according to the Oregon Historical Society’s Oregon Encyclopedia.
Cressman, who was married to anthropologist Margaret Mead from 1923-1927, helped found the anthropology department at the University of Oregon and its summer archaeological field school.
He was also the first director of what would become the Museum of Natural and Cultural History, the first museum in the state to curate archaeological remains, stated the Oregon Encyclopedia.
Cressman’s protocols at sites continue to benefit scientific knowledge, said Rose.
“This story demonstrates why the scientific process is so important in archaeology,” she said. “If (the team) rushed it or didn’t carefully control how evidence was gathered, they wouldn’t have been able to get this fine-grained data and to say with confidence that we need to shift the paradigm about the way we thought about the peopling of the Americas.”
