Morphometric measurements were used to classify 11 mustelid dentaries from Snake Creek Burial Cave (SCBC), a late Pleistocene to early Holocene—aged paleontological locality in eastern Nevada, that were undifferentiated between Mustela nigripes (black-footed ferret) and Neovison vison (American mink) due to their similar size and morphology. We, therefore, classified the SCBC fossils using 10 linear measurements of the dentary using extant M. nigripes and N. vison as proxy. Discriminant function and principal component analyses grouped the 11 unknown SCBC specimens within extant M. nigripes exclusively. Confirmation of M. nigripes at SCBC is significant because Cynomys spp. (their primary prey source today) have not been found at this site or other nearby Great Basin localities. Occurrence of this now-endangered taxon among the SCBC paleofauna and review of additional localities lacking Cynomys suggest that several geographically and temporally discrete prehistoric M. nigripes populations were sustained by other small mammal taxa. If this inference is true, facilitating dietary diversity in reintroduced M. nigripes populations could improve the species' resilience to future adversities, including anthropogenic climate change.