In 2019, Gray & Pape, Inc., conducted data-recovery efforts at the Hodges site (12MG564), a predominately late precontact Oliver phase (AD 1200–1450) site found in the White River valley of Indiana. Investigations of the site have fostered new ideas regarding the emergence of the Oliver phase. Previous models have suggested that the emergence of the Oliver phase was largely due to the migration of Fort Ancient groups into the region. Other models suggested that the region served as a frontier. The concepts of frontier interaction zones and fluid boundaries are presented here as the reasons for the emergence of the Oliver phase from in situ Late Woodland populations.