This study suggests that wolverines in Idaho are isolated from more northerly populations, which is most likely due to anthropogenic factors.

Abstract
“Our results suggest that wolverine populations from southernmost regions, in which anthropogenic factors are strongest, revealed more genetic structuring than did northern populations. Furthermore, these results suggest that reductions in this species’ range may have led to population fragmentation in the extreme reaches of its southern distribution. The continued reduction of suitable habitat for this species may lead to more populations becoming isolated remnants of a larger distribution of northern wolverines, as documented in other North American carnivore species.”

Discussion
“… we found the more southerly populations, in which anthropogenic factors are most pronounced, to be more genetically structured than those found in the north… A study by Paetkau et al. (1998) of North American brown bears (Ursus arctos) also reflects findings similar to those presented here. This is significant as both brown bears and wolverines have a similar distribution, density and potential for dispersal. In both these species, populations in the southern reaches of their range are more genetically distinct, and have less within-population variation, than those found in less disturbed northern habitats. Our results are also consistent with those found for another mustelid species, the North American pine marten (Martes americana)… We suggest that the level of genetic structuring in the southern reaches of this species’ distribution is the result of low effective population sizes, restricted gene flow and potentially population fragmentation, whereas the low level of structure in the northern regions is consistent with high levels of gene flow and few barriers to dispersal.”

Conclusions
“This study has shown that populations of wolverines that are exposed to fewer anthropogenic factors potentially have much gene flow among them. In direct contrast, the southern populations of Idaho and to a certain degree Revelstoke, which are exposed to greater pressure from humans (settlement, road systems, recreation in remote areas, and so on), seem to be more genetically isolated. The viability of these populations seems to be dependent, to a great extent, on large areas of undisturbed habitat and corridors among them.”