Paleoindian Settlement Decisions in the Great Basin: A Test of the Pluvial Lake Hypothesis with the Ideal Free Distribution Model

ABSTRACT Researchers propose that early Great Basin occupants preferentially settled near pluvial lakes to exploit highly profitable wetland habitats. Here we offer a preliminary systematic evaluation of this Pluvial Lake Hypothesis by testing two predictions from an ideal free distribution (IFD) model using a comprehensive database of radiocarbon-dated archaeological sites relative to reconstructed lake extent. We find that Paleoindian (> 8000 calendar years ago) settlements are significantly closer to wetlands than random across the Great Basin. However, when broken out by subregion (western, central, and eastern), the trend only holds for the western basin, likely because wetlands are so abundant in the central and eastern subregions that even random settlements fall within a 10-km foraging radius. The eastern subregion is the most suitable, having the lowest average distance to wetland habitats, and is the earliest occupied, which supports IFD predictions. This general pattern may help explain Paleoindian settlement patterns more broadly.