The species has been confirmed to have been native to northern Arizona since at least the Late Wisconsin late glacial period based upon pollen core analysis at the Waterman Mountains (Coconino County) - (not the Waterman Mountains of Pima County); dominant trees of Juniperus osteosperma and Pinus monophylla remain extant species to the present time in this predominantly Pinyon-juniper woodland.
Here in the Waterman Hills researchers found that Juniperus osteosperma and Pinus monophylla were early to mid-Holocene dominant trees, while Monardella arizonica has been a continuously present understory plant.