Building an Accurate Chronology of Fremont Maize Horticulture in Northwestern Colorado

Abstract The Fremont archaeological complex of the northern Colorado Plateau represents a mixed subsistence economy based on small-scale farming and foraging. However, the role of maize within the Fremont diet and its temporal span are poorly understood in northwestern Colorado, which is an eastern periphery of the broader Fremont tradition. Previous estimates in the region suggest that Fremont lifeways began early in the first millennium AD and persisted late into the 1600s. In this study, we examine 53 radiocarbon dates of maize macrofossils and short-lived wood/plant fragments from granary features from 33 sheltered and open-air sites in the study area. Based on our Bayesian modeling efforts, small-scale corn farming most likely began around cal AD 740–815 and ended between cal AD 1270 and 1320 , with a modeled duration of 515 years. Several peaks are apparent within the summed probability distribution (cal AD 970–1050 and cal AD 1090–1130), suggesting that the most intensive era for maize farming is coeval with social and subsistence trends evident across the broader Uinta Basin. We provide evidence of a restricted maize chronology throughout the study area, but further work is needed to understand the proportional contribution of maize to the Fremont diet.