Did Arroyo Formation Impact the Occupation of Snake Rock Village, a Fremont Dryland Agricultural Community in Central Utah, ca. AD 1000–1200?

Fremont farmers of the northern Colorado Plateau grew maize at the limits for cultivation in western North America between AD 300–1300. Like other Indigenous farmers throughout the American Southwest, Fremont farmers used bundled agricultural niches where alluvial floodplains were the largest available site for cultivation. But dryland floodplains are a risk to the persistence of farming communities because the development of steep-sided arroyos lowers floodplain surfaces and water tables, rendering them unusable for growing maize. This study tests the relationship between the occupational timing of Snake Rock Village between AD 970–1240 and the formation of a 4.5m deep arroyo on Ivie Creek adjacent to the site. I present a high-precision AMS radiocarbon chronology of the village occupation paired with an AMS radiocarbon reconstruction of the Ivie Creek floodplain 400m upstream from the site. The results of this study provide a direct test of arroyo formation as a cause for the abandonment of Fremont agriculture by AD 1300. The results indicated that the abandonment of Snake Rock Village does not correspond with an incision of the adjacent floodplain. Instead, the floodplain was still aggrading when Snake Rock Village was abandoned, and the incision did not happen until AD 1570 or AD 1725. Thus, while some evidence implicates arroyo formation as one factor contributing to the abandonment of early agricultural villages in other parts of the northern Colorado Plateau, arroyo formation did not appear to constrain the persistence of floodplain farming on Ivie Creek