Oregon Site Casts Doubt on Land-Crossing Theory

Researchers have found traces of a human presence on the Oregon coast dating to more than 10,000 years ago, raising the area’s importance for those who study the peopling of the Americas.

The findings at the Indian Sands site in Boardman State Park are more than 2,000 years older than previous discoveries along the Oregon coast. The site, about 12 miles north of Brookings, was excavated in August by a team of researchers from Oregon State University.

The discovery, which dates to the end of the last Ice Age, also lends weight to the theory that early inhabitants might have arrived by sea, rather than by land.

The discovery puts their arrival around the time that inland inhabitants arrived, bringing into question the theory that all of the earliest inhabitants crossed the Bering Strait and moved south overland to what is now the United States.

Excavators also found tools made of local materials and charcoal.

Roberta Hall, an Oregon State University anthropology professor, led the excavation team along with Loren Davis, a geoarcheologist and anthropology instructor at the university. Hall said the information will help tribal people, including the Confederated Tribes of Siletz and the Coquille Indian Tribe, learn about their ancestors and the challenges they faced. The tribes are collaborators in the research.

The findings are about the same age as a few sites in coastal Alaska, British Columbia and California. Determining the number of people who lived at the Indian Sands site, and for how long, would require a huge excavation, Hall said.

“What we did was just a preliminary test to see whether deposits from the late Pleistocene were preserved,” she said.

The team used three years of soil, geologic and other research as part of a different method of finding traces of the ancient people.

Typically, researchers note early signs of human activity and dig there. This project, however, involved analyzing sediments to figure out where they might find preserved materials and identifying attractive places where people would have wanted to live.

Hall said the discovery vindicates the newer research method.

The Indian Sands site is on the coast now, but Hall’s group determined that it was a mile or so inland 10,000 years ago. At that time, she said, the coastline would have been well west of where it is today. The coastline didn’t establish its modern location until about 6,000 years ago.

“It was a rocky outcrop, a really good source of quarry material,” Davis said. “They would have come inland for that.”

Hall said erosion and civilization complicated the archeologists’ work because they could find only undisturbed sediments in a small area. She said researchers found the tools, obsidian chips and charcoal about a yard down.

Davis said that the tools appear to have been made of native materials but that the obsidian, although common inland in the Oregon Cascades and elsewhere, does not occur along the coast. Further tests will determine its source and possibly reveal the mobility and trade patterns of the early people, she said.

Carbon-dating of charcoal indicated the site was 10,430 years old. But when the numbers are recalibrated, she said, they come out to more than 12,000 years.

The researchers have not determined whether the site will be expanded or if the methods will be used elsewhere along the coast.