PONDERING THE PEND OREILLE VALLEY: INDIGENOUS PLANT AND LAND USE AND LANDSCAPE FORMATION IN NORTHEASTERN WASHINGTON STATE

In the Pend Oreille Valley of northeastern Washington State, USA, intensive plant food processing sites are quite common. The 2023 archaeological field school at one such site, 45PO358, a collaboration between the Kalispel Tribe of Indians, Far Western Anthropological Group, and Washington State University, offered an opportunity to examine how and when these places formed, why people chose these locations, and how they made bulk plant food processing and storage decisions. In this paper, we present preliminary results of stratigraphic and macrobotanical analyses of natural and cultural strata in and adjacent to the site. These lines of evidence, combined with Bayesian modeling, are used to reconstruct site, local landscape, and land use histories. Specifically, we examine the Pleistocene-Holocene transition in the valley, formation of underlying and adjacent landforms, site deposition, macrobotanical signatures of local vegetation.