How does prehistoric material get from its place of origin to its location of archaeological recovery? While this question may seem basic, a moment’s reflection suggests that the answers carry important implications for arc-haeological interpretation about social organization, settlement, and subsistence practices. Archaeologists know much about the temporal and spatial distribution of materials in prehistoric western North America, but comparatively little has emerged regarding the causes of such distributions. Trade and exchange, mobility, and direct access all have been credited with observed distributions, but the reasons for settling on specific behavioral linkages is rarely made clear. This volume investigates the circumstances and conditions under which trade/exchange, direct access, and/or mobility best account for material conveyance across varying distances at different times in the past. Each chapter contextualizes distributional and chemical data, evaluates competing distribution hypotheses, and addresses the reasoning and inferences employed to arrive at conclusions about the human behaviors responsible for the distributions of materials. Contributors showcase a range of diverse and creative ways of thinking about these issues in the California and Great Basin archaeological record, and why it matters.