Early dispersal of Great Plains horses

The horse is central to many Indigenous cultures across the American Southwest and the Great Plains. However, when and how they were first integrated into Indigenous lifeways remain contentious, with extant models derived largely from colonial records. Here, we conduct an interdisciplinary study of an assemblage of historic archaeological horse remains, integrating genomic, isotopic, radiocarbon dating and paleopathological evidence. Archaeological and modern North American horses show strong Iberian genetic affinities, with later influx from British sources, but no Viking proximity. Horses rapidly spread from the south into the northern Rockies and central Plains by the first half of the 17th century CE, likely through Indigenous exchange networks. They were deeply integrated into Indigenous societies, reflecting in herd management, ceremonial practices and culture, prior to the arrival of European observers from the 18th century.