Younger Dryas environments and human adaptations on the West Coast of the United States and Baja California

On the Pacific Coast of the United States and Baja California, the Younger Dryas was one component of dynamic Late Pleistocene and Holocene environmental changes. Changing climate, sea level rise, and shifting shorelines created ecological challenges for ancient coastal peoples and daunting challenges for archaeologists searching for early coastal sites. This paper reviews the evidence for ecological change in this ‘West Coast’ region, including shoreline changes that may have submerged or destroyed archaeological sites from this time period. Examining the regional record of human occupation dating to the Younger Dryas, well-dated coastal sites are limited to California’s Northern Channel Islands and Isla Cedros off Baja California. A small number of fluted points found in coastal areas may also date to the Younger Dryas, but their context and chronology is not well defined. Review of the implications of these two data sets considers whether the early but discontinuous Younger Dryas archaeological record from the West Coast might result from a migration of maritime peoples from Northeast Asia into the Americas.