Infection with Elaeophora schneideri, a filarial parasite, occurs commonly in mule deer (Odocoileus hemionus) and elk (Cervus elaphus nelsoni), but seemingly less so in moose (Alces alces). Of 109 carotid artery samples from moose harvested throughout Colorado, USA, in 2007, 14 (13%; 95% binomial confidence interval [bCI]=7–21%) showed gross and 91 (83%; 95% bCI=75–90%) showed histologic evidence of elaeophorosis. Although neither blindness nor other clinical signs associated with elaeophorosis were reported among the harvested moose we examined, the pervasiveness of this parasite may motivate further study of the potential effects of elaeophorosis on moose survival and population performance in the southern Rocky Mountains. Our data suggest histopathology may be more sensitive than gross examination in detecting elaeophorosis in harvested moose.