Bighorn Sheep (Ovis canadensis) historically inhabited the Black Hills region of South Dakota, but the species was extirpated from the area in the early 1900s concurrent with declines in population throughout their entire North American range. Translocation is a common management tool allowing for accelerated colonization of historic Bighorn Sheep habitat, but many attempts are unsuccessful. Mountain Lions (Puma concolor) and pneumonia are generally considered the most common limiting factors to Bighorn Sheep populations. Twenty-six Bighorn Sheep were translocated from Alberta, Canada to the Deadwood region of the northern Black Hills, an area with both a resident Mountain Lion population and potential for contact with Domestic Sheep (Ovis aries) and Goats (Capra hircus), known carriers of pathogens that are lethal to Bighorn Sheep. Adult survival and natality increased the population substantially in year 1, however, the only breeding-age male was euthanized owing to concerns about potential for pathogen transmission from Domestic Sheep and Goats. In year 2, the population experienced a pneumonia outbreak, resulting in 57.9% of all mortalities during the study period. Mountain Lion predation was not detected, nor was direct contact with Domestic Sheep or Goats observed. Intensive monitoring was critical in determining the outcome of the translocation.