CORVALLIS - A team of researchers from Oregon State University has found evidence of human presence on the Oregon coast dating more than 10,000 years ago - more than 2,000 years older than the earliest known archaeological sites on Oregon's coast.
The Indian Sands site is in Boardman State Park, about 12 miles north of Brookings on the southern Oregon coast. The site was excavated last August by a team lead by Roberta Hall, an OSU anthropology professor and principal researcher on the project, and Loren Davis, team geoarchaeologist and anthropology instructor at OSU.
Oregon Sea Grant funded the study.
The Indian Sands findings are older than known sites on the Washington coast and approximately the same age as a small number of sites in coastal Alaska, British Columbia and California.
This finding places the Oregon coast in a new and important strategic position in the study of the peopling of the Americas, according to Hall.
"The Oregon coast has a story to tell," Hall said. "It can help earth scientists, native people, and all the communities along the Oregon coast understand the environments that are of great interest to them."
Finding coastal sites that would have been attractive to ancient dwellers is difficult. Most of what was the Oregon coast thousands of years ago is now under water. As the glaciers of the last ice age melted, they raised the level of the ocean. What was once the coast is now anywhere from hundreds of feet to more than a mile offshore.
Further, the Oregon coast is a dynamic landscape, buffeted by wind, rain, earthquakes and tides. Intense study of the site by Hall's team suggests that 10,000 years ago it was about 1.5 kilometers inland. But the researchers thought characteristics of the site as it existed would have drawn early visitors.
"It was a rocky outcrop, a really good source of quarry material," said Davis. "They would have come inland for that."
At about the 40- to 50-centimeter depth of their 1-meter by 2-meter hole, the researchers found stone artifacts. "This particular site has a floor with at least partial stone tools in the same level," Davis said. The artifacts were "a modest amount of flaked stone, chipped by humans."
Importantly, they also found charcoal at the same level. Carbon dating of the charcoal provided the 10,430-year age of the site, which conformed to older dates he had previously obtained by dating sand samples at lower levels. According to Hall, 10,430 radiocarbon years translates to between 11,690 and 12,930 "real chronological years" ago.
"It truly is late Pleistocene," she said.
Along with the stone artifacts that appeared to have been made from local rock sources, the researchers found bits of obsidian, which could not have come from the site. Future tests will permit the team to determine the source. This could lend evidence concerning the mobility of these early people and could tell how widespread their trading networks might have been.
The context of the finds should convince even the most skeptical, Davis said. University of Oregon archaeologists several years ago dated burned shell from an exposed midden in a stratum lying above that excavated by the OSU team. Thus all of the dates - the UO surface dates, the recently dated charcoal from a buried midden, and the older, deeper dates - are in agreement.
Finding a truly ancient site along the southern Oregon coast, one that dates to the end of the last Ice Age, is significant for many reasons, Hall said. First, its age lends more weight to the theory that early inhabitants might have arrived in the region by sea rather than - or as well as - from land migration on the continent. For years scientists believed humans arrived in the Western hemisphere during the Ice Age via a land bridge over what it now the Bering Strait, then moved down the continent and out to the coast. New evidence suggests that humans might have arrived by sea, moving up the coast of Asia, then down the coast of the Americas, making Oregon an early site of habitation.
The discovery supports the theory that human settlement of the continent is substantially older than previously believed. This information is potentially useful to environmental scientists and cultural resource managers, but is of potentially even greater importance to tribal people, including the Confederated Tribes of Siletz and the Coquille Indian Tribe, who are collaborators in this research, because it provides additional information about their cultural forebears and the challenges they faced.
The OSU project also validates the process by which the site was located. Typically, researchers take early signs of human activity as the clue for deciding where to dig. Hall and her fellow researchers had to try a different approach. Almost two years of paleo-ecology, soil and geologic research went into looking for a site that would have features that would have been attractive to ancient people.
The Indian Sands site was chosen after two years of surveys that included soil and radiocarbon testing. Michele Punke, a graduate student in geosciences and a geographic information systems (GIS) specialist, served as field assistant through the survey project and her analyses confirmed the location's potential. Among other things, her studies showed that the coast line would have been very close to the current coast 8,000 years ago, and at 10,000 years ago it would have been only a few kilometers west.
"We knew this was an interesting place to look," Davis said. He and Matthew Fillmore, a USDA soil scientist who is housed on the OSU campus, conducted soil studies there and at other coastal locations a year earlier, and the visit to many coastal sites helped him make this decision. Still, with all the changes that have occurred on the coastline, when it came time to actually pick a spot for a 1-meter by 2-meter hole, he admits he felt some trepidation.
"There was a lot of pressure," Davis said.
But the August 2002 dig went well. In a week the team had excavated about 40 to 50 centimeters, and they found what they were looking for.
Hall, Davis and Punke are now preparing the findings for professional publication.
The three-year project grew out of 26 years of collaborative research between the Coquille Indian Tribe and an OSU team led by Hall. The project began in 1976 when tribal members requested Hall to help them recover and reconstruct their cultural history. Many individuals and agencies joined in the work, including cultural, environmental, archaeological and biological studies.
In addition to support from local agencies, the field research foundation Earthwatch provided funding and volunteers from all over the country on three intensive projects involving oral histories and archaeology. Various resource and political agencies such as U.S. Fish and Wildlife, the City of Bandon, the Port of Bandon, the Bureau of Land Management, and the Bandon Historical Society have also contributed.
Don Ivy, cultural resource coordinator for the Coquille Indian Tribe, is an associate investigator on the project; his team's research has complemented the OSU team's investigations, and the tribe, along with various federal agencies, has provided essential field and informational support, Hall said.
Further information on the projects can be obtained on the web at http://osu.orst.edu/dept/anthropology/SeaGrantWeb/index.html.