A review of bat specimens housed at the University of Alaska Museum confirms the occurrence of the Yuma Myotis (Myotis yumanensis) in Southeast Alaska. This represents only the 7th bat species known from the state and its 1st new bat in >40 y. All known specimens of the Yuma Myotis were collected in the early 1990s. Reasons why this species escaped detection until now are discussed and include its close morphological resemblence to the more common and widespread Little Brown Myotis (Myotis lucifugus), the general inaccessibility of much of Southeast Alaska, and a historical paucity of field and specimen-based studies of bats from this region. The presence of the Yuma Myotis in Alaska, while not surprising, suggests that we still have much to learn about the basic biology, ecology, and biogeography of this and other bat species in and around Alaska. Such information is critical if we are to monitor the effects of climate change and other anthropogenic factors on organisms at the limits of their geographic distributions.