Geographic range: Nearctic - Neotropical: Endemic to Mexico. Found in western Sierra Madre and central Mexican highlands from south eastern Chihuahua and Coahuila up to the central Nuevo Leon, south to the central Oxaca.

Physical characteristics: A slightly robust snake reaching 150 - 200 cm in length. Neck moderately pronounced. Pupils round. Pattern of saddle - shaped spots running the length of the dorsum. Body color is pale sandy to orange (apparently age dependent) Number of spots is used to identify subspecies.

Food habits: Mainly rodents, but also other small mammals and birds.

Reproduction: Average clutch 5 - 10 eggs (captivity).

Behavior: Although secretive in habits, this species is known to defend itself actively and bite when approached.

Habitat: Pine (and pine - oak) forest and high-elevation desert habitat.