Investigations in the Cahokia Site Grand Plaza

Abstract
Research designed to explore the Grand Plaza at the Cahokia Mounds site, the largest Mississippian-period mound center in the eastern United States, documents that plazas may yield significant information regarding Mississippian manipulation of the landscape and the initial growth of mound centers. Probing and excavation within the Grand Plaza revealed that buried ridge-swale topography, identified through an electromagnetic-conductivity survey, was stripped and then filled by the Cahokians. Excavation also corroborated the presence of deep-pit borrows identified by remote sensing. Based on the ceramics recovered from our excavations, we argue that these earth-moving events were initiated prior to the onset of the Mississippian period (ca. A.D. 1000). Reclamation of the borrowed areas resulted in the formation of the mound-plaza configuration early during the Mississippian period.