Dating the Western Stemmed Tradition and Nimíipuu traditional subsistence practices

By John Blong, assistant professor of archaeology

The discovery of a 16,000-year-old hunter-gatherer camp at the Cooper’s Ferry site in northern Idaho significantly changed our conception of the timing of the initial settlement of the Americas. The earliest occupation at Cooper’s Ferry contains diagnostic Western Stemmed Tradition (WST) stone projectile points that are also found in 14,500-year-old deposits at Paisley Caves in southcentral Oregon. However, some researchers question this evidence, suggesting instead that the WST represents a later archaeological culture, postdating the Clovis archaeological culture established across North America 13,000 years ago.

A crucial issue driving these questions is the lack of multiple well-dated WST sites that can be used to develop a chronology of initial settlement. This has bearing on our understanding of the process of the settlement of the Americas, with some researchers suggesting that WST represents the earliest settlement by people traveling down the western Pacific coast.

To work towards a better understanding of the WST on the southern Columbia Plateau, a team of anthropology undergraduate and graduate students is excavating at the Kelly Forks Work Center Site, located in the Bitterroot Mountains, Idaho. Excavations at the site over a decade ago produced WST stone points, but the age of this WST occupation is not well established.

Our team is conducting a detailed analysis of the WST sedimentary contexts and using fine-grained artifact recovery and dating techniques to reconstruct the natural and cultural processes that formed the site. These data will allow us to situate the site in the broader context of the settlement of North America.

Moving beyond the timing of the initial settlement of the Americas, we still have much to learn about the day-to-day lives of these initial settlers. Techniques developed in archaeological science can be used to investigate the otherwise invisible clues of past diets and land-use patterns. The Kelly Forks site is within the Nimíipuu (Nez Perce) homelands, in an upland area traditionally important for late summer and early fall subsistence activities. Archaeological evidence suggests that this seasonal subsistence round may extend back tens of thousands of years to the WST period; however, the evidence is currently sparse.

We are studying microscopic plant residues such as pollen, phytoliths (silica casts of plant cells), and starch grains (crystalline glucose structures) from sediments and stone tools from Kelly Forks to investigate ancient diets and establish the time of year the site was occupied. The research design for this project was developed in consultation with the Nimíipuu Tribe, and these analyses will provide information on upland harvesting practices important to the Nimíipuu. WSU Anthropology will return to Kelly Forks in the summer of 2023 to continue our work at this important site.

Field researchers.
Excavations at the Kelly Forks Work Center site.