The Trincheras Heartland in the Wake of Migration: Exploring Cultural Change and Continuity at Fourteenth Century Sites in Sonora’s Altar Valley

Between 400 to 1450 CE, the Trincheras tradition spanned north-central Sonora and extreme southern Arizona. Since the 1950s, archaeologists have argued that dramatic transformations around 1300 CE impacted the Trincheras heartland. These transformations included a proposed influx of Papaguerían Hohokam migrants, the adoption of new cultural practices, expansive trade networks, and changes to local lifeways. Scholars have also suggested that local Trinchereños gradually depopulated the region; however, sites in the Altar Valley have never been subject to excavation or critical evaluation. This paper utilizes a multivariate approach on two newly excavated sites within the Altar Valley. We argue for the presence of migrant-brought materials during the late 1200s/early 1300s and suggest that groups from the southeastern Papaguería gradually entered the region and coalesced with Indigenous Trinchereños. This paper contributes to migration studies across the late precolonial Southwest/Northwest and offers a much-needed reevaluation of the late prehistoric period within the Trincheras heartland.