Theses and Dissertations Collection

Archaeological investigations in the 1990s defined the Clearwater River region of the southern Columbia Plateau as a unique cultural and archaeological entity, though it remains poorly understood. Excavations throughout ancestral Nez Perce country have revealed vitrophyre in at least 19 key sites dating back 12,000 years. Vitrophyre is a natural igneous glass, formed of pyroclastic flow deposits containing large-grain phenocrysts of ash and pumice. Much like obsidian, vitrophyre creates sharp cutting edges for tool production and retains a chemical signature that can be traced to a parent source. A combination of pioneering geochemical analysis, lithic analysis, and experimentation have provided an overview of this understudied resource and its uses. By comparing two known vitrophyre sources with the archaeological record through an ecological foraging model, vitrophyre use reflects both embedded procurement strategies and territorial restrictions of different groups since the initial occupation of the Clearwater River region. Archaeological and ethnographic data information suggest a strong connection with Salish groups of the Bitterroot and Plains regions.