In 1921, the founding of the Rocky Mountain Laboratory (RML) can be traced back to westward migration when early settlers in the Montana foothills of the Bitteroot Range of the Rocky Mountains were plagued with a disease known as “black measles,” or “spotted fever,” now known as Rocky Mountain spotted fever.

In 1902, the U.S. Public Health Service sent out a research team to find the cause. In 1906, Dr. Howard Ricketts, a young pathologist from the University of Chicago, showed that the disease was transmitted by the bite of the Rocky Mountain wood tick (Dermacentor andersoni). By 1909, he had isolated the bacterial organism that was responsible for spotted fever, and that organism was later named Rickettsia rickettsii in his honor.