evalence ??? 200-400 cases per year in the U.S.Transmission ??? tick (Dermacentor andersoni); reservoir species (small rodents, including chipmunk, squirrel, rat)Infection rate highest in Rocky Mountain region of North America at elevations above 4,000 feetOrganismColtivirus genus and Reoviridae familyDouble-stranded RNA arbovirusClinical PresentationIdentical to ehrlichiosis ??? macular rash in 5