Edward D. Cope (1866) described the Arizona Mountain Kingsnake from a specimen collected in Beaver Canyon, Utah. Prior to 2011 the Arizona Mountain Kingsnake, Lampropeltis pyromelana, was once considered a single species that extended from Sonora, Mexico northward into Nevada and Utah.

Burbrink et al. (2011) sampled DNA from different localities within L. pyromelana’s range and found two lineages. One from the Colorado Plateau and one from the Sierra Madre. The two lineages are separated by low elevation habitats. The northern Colorado Plateau and Mogollon Rim populations and the southern populations in the Madrean Archipelago and the Sierra Madre Occidental are not in contact. Because Cope described the species from Colorado Plateau lineage, the northern population keeps the name Lampropeltis pyromelana.

The southern lineage had been described from Mojarachic, Chihuahua, Mexico by Edward Taylor in 1940 as L. p. knoblochi. And again, by Wilmer Tanner in 1957 from specimens collected in Carr Canyon, Huachuca Mountains, Arizona as L. p. woodini. This required Burbrink et al, (2011) to remove Taylor’s name from the synonym of Lampropeltis pyromelana and apply it to the southern lineage.

The result demonstrated two lineages of unequal population sizes. The speciation event separating the two lineages likely occurred before the Pleistocene, during the aridification of the southwest or the uplift of the Colorado Plateau. The Arizona Mountain Kingsnake to the north and Knobloch’s Mountain Kingsnake to the south. Both species use similar high elevation niches, but they are isolated from each other by the low, inhospitable desert.