The settlement of the Americas represents the most extensive and rapid biogeographic expansion of our species. My working group is studying how this settlement process took place in western South America. I will share new insights from our team’s excavation and dating of sites from the Pacific Coast to the high Andes and outline an approach combining survey, provenance analysis, and GIS path modeling to trace human movements. Ultimately, the goals of this work are to understand migration routes, processes of adaptation in extreme environments, and inter-zonal connections in the Andean world.