Thesis (M.S.) University of Alaska Fairbanks, 2000The Prince of Wales flying squirrel (Glaucomys sabrinus griseifrons), a forest associated species, is endemic to several islands in the Alexander Archipelago of Southeast Alaska. Mitochondrial and nuclear markers were examined to assess the genetic uniqueness of this subspecies and its geographic extent and to investigate gene flow among island and mainland populations of flying squirrels. Data from both sets of markers are congruent, and agree with the subspecific designation. The data also indicate that the Prince of Wales subspecies is isolated from other populations in Southeast Alaska, but that there may be gene flow among islands on which it occurs. This island lineage is likely the result of a founder event after the retreat of the Pleistocene ice sheets. The fact that this subspecies is isolated and divergent from mainland populations has potential implications for the design and planning of timber harvests on these islands