The White Mountain arctic butterfly [WMA;Oeneis melissa semidea (Say)] is endemic to the alpine zone of Mts. Washington and Jefferson, New Hampshire, USA, and because of its small and declining population size, it is considered threatened. White Mountain arctic adults occur only within four alpine meadows, and it has been suggested that dispersal, and hence gene flow, may be restricted among these meadow subpopulations. Furthermore, although the WMA likely is biennial (i.e., requires 2 years for development) like all other species of Oeneis, adults emerge annually. Thus the WMA population may be further structured into two allochronic cohorts, reproductively isolated by their asynchronous adult emergence in either even-or odd-numbered years. We assessed the spatial (among meadows) and temporal (between even-and odd-year cohorts) genetic structure and diversity of the WMA using mtDNA and AFLP markers generated from non-lethally sampled wing and leg tissue. We found no evidence for restricted gene flow among meadows. AFLPs indicated weak differentiation between alternate year cohorts; however, it remains unclear whether this resulted from allochronic reproductive isolation or genetic drift. Despite the WMA's small population size and isolation, levels of AFLP genetic diversity were generally high. Rather than focusing on factors related to population connectivity and adult dispersal, our results suggest that management efforts for the WMA should instead focus explicitly on factors affecting recruitment and mortality.