A GIS Model of Shell Exchange Between Southern California And Northern Arizona

Description

Shell was traded into the United States Southwest from various areas, one of which was coastal Southern California. Abalone shell, or Haliotis, is solely sourced from the Pacific coast and provides irrefutable evidence of this trade. This exchange likely involved many Indigenous groups between the sourcing area and the shell’s inevitable endpoints. Historical documentation of trails for facilitating exchange exists, but modeling a route in a spatial analysis program has not been attempted for this transregional exchange. Utilizing least cost path analysis in ArcGIS Pro provides a theoretically most efficient route of abalone shell from the Chumash and Gabrielino Indigenous groups to seven archaeological sites in Northern Arizona and one just across the Utah–Arizona border in Kanab, Utah. The results of the model are mixed. It partially matches with historic documentation in California but is more consistent with the U.S. Southwest trail documentation. Further model refinement is proposed to incorporate hydrographic data, a modified Tobler’s hiking function for more accuracy, incorporate more documented sites on the Southern California coast and further inland, and complete additional modeling between destination sites. Still, the model presented here is a first step to further evaluating Southern California–Southwest exchange and shell procurement.