It was endemic to Arizona in the United States, where it occurred in the Santa Rita Mountains before being declared presumed extinct.

They lose their wings and ability to fly after returning to water as adults where they spend the remainder of their lives underwater.

[6] Additional paratypes were provided to the British Museum of Natural History (London), the National Museum of Natural History (Washington, DC), the University of Arizona (Tucson), the Illinois Natural History Survey (Urbana), the California Academy of Sciences (San Francisco), the University of Oklahoma (Norman), and the private collection of Karl Stephan.

[2] The known habitats of Stephan's riffle were only in Madera Canyon, on the west flank of the Santa Rita Mountains in Coronado National Forest (southeastern Arizona, United States).

[4] The United States Fish and Wildlife Service (USFWS) declared the beetle needed conservation in 1984.

[3] In 2016, the service announced that the beetle had not been observed for twenty years and was considered extinct.