Until recently it was assumed that fishers (Martes pennanti) in the Rocky Mountains all were descended from reintroduced stocks. However, a recent study reported that mitochondrial DNA (cytochrome-b and control region) haplotypes of fishers found only in west-central Montana are likely derived from a relic population of fishers that escaped harvests conducted in the early 20th century. I compared fishers in west-central Montana to samples from north-central Idaho and found no evidence for substructure between these groups. A museum specimen, collected in 1896 in north-central Idaho before any known translocation, also was the same haplotype as the “native Montana haplotype” discovered in the recent study. Thus, fishers in north-central Idaho and west-central Montana are the only confirmed native fishers in the Rocky Mountains, and 1 of a few populations in the West that have maintained native genes. Fishers from Idaho and Montana are not all descendants of translocated individuals, but also are the descendants of fishers that persisted despite early 20th century trapping.