This paper presents the results of the Etsel Ridge Archaeological Project, the 1986 phase of an ongoing cooperative agreement between the Bureau of Land Management, Sonoma State University Anthropological Studies Center, and Santa Rosa Junior College. Data from this survey, together with data from earlier work in the area are synthesized from both surface and subsurface contexts and utilized to explicate chronology, adaptive patterns, and obsidian exchange. A tentative model of diachronic settlement and subsistence is proposed for the Etsel Ridge locality. Obsidian sourcing and hydration data from Etsel Ridge are compared to similar data from the adjacent Middle Eel lowlands. Both spatial and temporal variability in the use of Borax Lake obsidian are explored.