Rocky Mountain wood tick: A tick that can transmit R. rickettsii, the agent of Rocky Mountain spotted fever. This tick is found in the Rocky Mountain states and in southwestern Canada. The life cycle of this tick may require up to 2 to 3 years for completion. Adult ticks feed primarily on large mammals. Larvae and nymphs feed on small rodents. The scientific name for the Rocky Mountain wood tick is Dermacentor andersoni.