COASTAL MIGRATION INTO THE NEW WORLD: CHALLENGES TO EARLY ARCHAEOLOGICAL SITE DISCOVERY IN COASTAL RIVER VALLEYS

Recently, renewed interest in a coastal migration hypothesis of initial entry into the New World has inspired archaeological studies designed to locate late Pleistocene sites on the Northwest Coast of North America. Models of coastal migration often include an element of inland mobility via river corridors following initial colonization of coastal areas. To date, no evidence of late Pleistocene human occupation on the Northwest Coast has been discovered from coastal river valleys due, in part, to the dynamic geomorphic forces that altered the landscape during and after the late Pleistocene. While the processes of how landscape change during rising sea level affects the distribution of coastal sites is generally understood, the specific effects and timing of post-glacial alluvial adjustments along the Northwest Coast is less clear. Addressing this problem, this poster reports the results of subsurface sediment coring at a locality ca. two kilometers from the Pacific Ocean on the Sixes River, in southern Oregon, USA, and its implications for discovering early archaeological sites in coastal river valleys.