The Grenfell bone rod resembles other instances of Clovis-era organic or osseous technology and has on a number of occasions been considered with other Clovis bone, antler, and ivory rods or beveled artifacts. It had been suspected of being constructed from proboscidean long bone. As an early discovery (made in 1883), the Grenfell artifact had somewhat obscure provenience details and a lengthy curatorial history. We describe accelerator mass spectrometry and zooarchaeology by mass spectrometry methods that allow rapid, minimally destructive determinations of both the age and the raw material composition of osseous artifacts. Our analysis reveals that the Grenfell artifact is actually a terminal Paleoindian-era manifestation made of bison bone. Similar methods could be more widely applied in North America in order to build more refined data sets for osseous technologies. These results also reveal the ease with which archaeologists can secure additional information from existing collections, highlighting our ethical obligations to do so.