The natural host, reservoir, and vectors (agents responsible for disease transmission) for Rocky
Mountain Spotted Fever are ticks. Two ticks, Dermacentor variabilis, also known as the
Rocky Mountain wood tick, and Dermacentor variabilis, the “American dog tick,” are the primary vectors seen in North America. Recently, however, Rhipicephalus saguineus was found to be the vector involved in an outbreak of RMSF in Arizona.