We photo-verified the presence of a wolverine (Gulo gulo) in California for the first time in 86 years during February 2008. Herein we document the process of determining the origin of this wolverine using genetic, stable carbon (δ13C) and stable nitrogen (δ15N) isotope information. The wolverine’s origin was significant because it is a state-threatened species and California represents a historically unique genotype of wolverines in North America. We obtained both photographs and noninvasively-collected genetic evidence (scat and hair). DNA analysis revealed the animal was a male and not a remnant of a historical California population. Comparison with available data revealed the individual was most closely related to populations from the western edge of the Rocky Mountains. This represents the first evidence of connectivity between wolverine populations of the Rocky and Sierra Nevada Mountain Ranges.