Classic-period settlement in the Teuchitlan region of West Mexico is characterized by the presence of unique, formal circular structures surrounded by residential areas. Previous research in the area has suggested the presence of a four-tiered settlement hierarchy based on the size of these structures, although, to date, this judgment has been made on a largely impressionistic basis. Our research further examines Weigand's Teuchitlan settlement data. We present a theoretical perspective for understanding the role of sites with formal architecture and evaluate the presence of a site-size hierarchy through volumetric estimations. Scenarios for site interaction are suggested by our use of a gravity model. Our primary goal is to propose models of Teuchitlan settlement organization, which can be tested by ongoing fieldwork in the region.