Isotopic Evidence Supports Existence of Late Holocene Bison Herds in West Central New Mexico

Modern bison (Bison bison) populations have experienced dramatic shifts in the last millennium, resulting from climatic fluctuations, human settlement growth, and overhunting. While bison populations are rebounding in some parts of the Southwest, the original extent of their range in this region is not clear. In west central New Mexico, the presence of bison bones at Prehispanic sites could indicate the presence of local herds, but they could also have been items that were exchanged or brought from the east, including the Great Plains. This pilot study uses strontium (87Sr/86Sr) and lead (206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb) isotope analysis to determine whether the bison remains found at five sites in the vicinity of the Plains of San Agustin may have originated from that area. While no wild bison exist on the plains or in western New Mexico today, combined zooarchaeological and preliminary isotopic data indicate they had lived alongside communities in the region for centuries, and possibly millennia, before European contact.