10,000-year-old stone tools with animal tissue residue unearthed in Washington State
After the glaciers retreated during the end of the last Ice Age in North America, people quickly moved in and inhabited the areas free of the ice. One such site, in the Puget Sound area of Washington State in the Northwest United States, has been under excavation, and archaeologists have found thousands of worked stone tools from millennia ago. One tool dating back 10,000 years, a time when shaggy-haired mammoths and prehistoric bison roamed the area, was found to have animal-tissue residue on it.
The site, at Bear Creek south of the city of Redmond, was discovered in 2009 during a routine archaeological survey in advance of a project to mitigate channeling of the creek. Bear Creek is a tributary to the Sammamish River.
Archaeologists found more than 4,000 stone flakes, spear points, awls and scrapers that Native Americans made 10,000 years ago or more. Archaeologists analyzed one of the tools to find traces of food the Indians ate, including salmon, sheep, deer, bear and bison.
The excavation and research were done by SWCA Environmental Consultants, headed in the field by Robert Kopperl. The team wrote a paper about their findings at the journal PaleoAmerica.
Skeleton of an ancient bison of the type found in North America during the Ice Age (Photo by James St. John/ Wikimedia Commons )
“We were pretty amazed,” Kopperl told the Seattle Times. “This is the oldest archaeological site in the Puget Sound lowland with stone tools. This was a very good place to have a camp. They could use it as a centralized location to go out and fish and hunt and gather and make stone tools.”
The excavations at first revealed few artifacts of note near the surface. But then, in 2013, the crew ran into a layer of peat, under which the remarkable assemblage of stone tools was located.
The bottoms of two spear points have rare concave bases. They are unlike the tools of the Clovis culture, which have more graceful fluting.
“Expedient tools include hammerstones and edge-modified flakes and cobbles,” the scientific paper says. “The formed tool assemblage includes bifaces, scrapers, gravers, projectile points, and unifaces. Raw materials are dominated by metasediment and fine- to coarse-grained volcanic rock. Formal tools are made of chert and fine-grained volcanic rock. Three distinctive projectile point bases were found in situ during the 2009 and 2013 excavations, two of which are concave-based and one of which may be part of a stemmed projectile.”
The city of Redmond and state of Washington have delayed a project to restore riparian habitat for salmon in Bear Creek to allow the archaeological work to continue. The stream was confined to a rock-lined channel many years ago.
The peat was undisturbed, so archaeologists say the artifacts predate its formation. Radiocarbon dating of the peat and charcoal that was with some of the tools shows they date back around 10,000 years. The scientific paper says the team found evidence humans lived in the landscape between 8,000 and 16,000 years ago.
A view of the Sammamish River in King County, Washington; Bear Creek is a tributary. (Photo by Fenixfyre/ Wikimedia Commons )
Because there are so many trees and because the ice sheet disturbed the land west of the Cascade Mountains, there are only a few known sites going back more than 10,000 years in the region. At one site 12,000-year-old mastodon bones were found, near Sequim; and the other site had bison bones on Orcas Island, also about 12,000 years ago. Neither of those sites included stone tools.
Another handful of sites have been found east of the Cascades from 12,000 to 14,000 years ago that did have stone tools.
Allyson Brooks of the Washington State Historic Preservation office said most of the streams and waterways in the region were inhabited or used by prehistoric Native Americans. She said it shows that people continuously use the same lands today that people used years ago.
Excavations in the 1960s at Marymoor Park south of Bear Creek showed evidence of habitation there around 5,000 years ago, Brooks said.
Featured image: The stone tools found at Bear Creek include the upper two in the photo with rare concave bases. ( PaleoAmerica journal photo )
By Mark Miller