General Description: Southern Pacific Rattlesnakes (Crotalus oreganus helleri) are medium-sized, heavy-bodied snakes with broad, triangular-shaped heads and rattles on the tail. A white facial stripe extends from behind the eye to the corner of the mouth. The dorsal pattern is variable, but the ground color is dark with white lines that separate dark blotches, but there is no dark between the dorsal blotches. Black and white tail rings.

These snakes are venomous. Do not attempt to handle rattlesnakes; rather, enjoy your good luck of finding one from a distance (minimum 4 feet away) and leave them alone.

Taxonomy: Pit Vipers Family (Viperidae). This was a subspecies of the Western Rattlesnake (Crotalus viridus), but the Western Rattlesnake was split into (1) Prairie Rattlesnake (Crotalus viridus) of the Great Plains and (2) the Northern Pacific Rattlesnakes (Crotalus oreganus) of the Inter-mountain and Pacific states. The Southern Pacific Rattlesnake is now Crotalus oreganus helleri.

Range: The species range extends from southwestern Canada to northern Mexico, and from the Pacific Coast east to Idaho, western Wyoming, and western New Mexico. This subspecies occurs in coastal southern California and northern Baja California.