Book excerpt: Purpose: This thesis synthesizes extant information relating to the prehistory of the upper Cache Creek watershed that helps to contextualize prehistoric cultural resources in the Bureau of Land Management Indian Valley/ Walker Ridge Recreation Area (IV/WRRA), Lake and Colusa Counties, California. The purpose is to create an inventory document that provides cultural resource management practitioners and land managers with an informed basis for understanding the study area in terms of the cultural resources, their environment, land use in the past, and the need for further work. Methods: Archival, literature, and geographical information systems research was conducted to: (1) integrate ethnographies of the Hill Patwin to provide context for interpretation of prehistoric cultural resources; (2) synthesize the regional prehistories of the southern North Coast Ranges and the Sacramento Valley; (3) determine the location and the scope of previous archaeological surveys and archaeological sites within the IV/WRRA and vicinity; and (4) investigate management obligations and create recommendations for the management of cultural resources within the IV/WRRA. Findings: The IV/WRRA and surrounding area was not simply a backwater located between two more populated and culturally elaborate regions. It had a large native population with multiple sociopolitical groups and contained a portion of the extensive exchange network that connected the Pacific coast, the Clear Lake basin, the Central Valley, and the Sierra Nevada. This makes it an excellent locale for the study of cultural transmission between these regions. Conclusions: The upper Cache Creek watershed was a locus for cultural exchange between the Clear Lake basin and the Central Valley, and between the Pomo peoples and the River Patwin. The prehistoric inhabitants, the Hill Patwin, were tied culturally and socially to both groups and culture regions. Greater inclusion of the Hill Patwin into the North Coast Ranges cultural region and viewing them as the locus for the movement and transmission of cultural practices and elements between these two regions provides a better basis of analysis of the late prehistoric era of the area. Social boundary studies and material culture studies are two avenues of research that can greatly contribute to the understanding of the social dynamics of the region. Many aspects of material culture can be examined to look at the similarities and differences between these different groups and the ways that these characteristics may have been passed through this region.