Immunization of desert bighorn sheep (Ovis canadensis) against bluetongue virus was attempted by inoculation of live virus vaccine with a syringe and needle, by experimentally contaminated Culicoides gnats, the natural biological vectors, by bites of exposed Stomyxis calcitrans, which were considered to be natural mechanical vectors, and by incorporation of lyophilized vaccine in ground dry feed. Only the methods using the syringe and needle and the natural biological vector were effective.