Copepods of the genus Salmincola (gill lice) parasitize salmonids. We collected kokanee salmon (Oncorhynchus nerka) from a reservoir in Colorado to identify the species of gill lice present and investigate intensity and prevalence of infestations. We observed increasing intensity and prevalence with age of fish. Our study adds to limited knowledge of infestations of Salmincola in Colorado and the western United States.