Rocky Mountain Wood Tick (Dermacentor andersoni)

The Rocky Mountain wood tick (Dermacentor andersoni) is one of two major vectors in the United States of Rocky Mountain spotted fever (Rickettsia rickettsii), a bacterial zoonosis transferred to humans from small rodents via a tick vector. Only members of the hard tick family Ixodidae are naturally infected with Rocky Mountain spotted fever, including the widespread American dog tick, D. variabilis, found east of the Rocky Mountains and in limited areas of the Pacific Coast.