Rather than stripes, the Durango rock rattlesnake stands out due to the rounded, ovular blotches running down the length of their back. They can be gray, tan or brown; and usually have a "rough" textured pattern of speckles slightly darker than the body.

This subspecies is found in humid pine-oak forests and chaparral of Durango, Sinaloa and Nayarit, along the Pacific versant of the Sierra Madre Occidental. Its preferred microhabitat is rocky slopes and grass with abundant grass cover.

Centipedes and lizards make up the majority of this snake's diet.

Their rattles are extremely small, and often inaudible to humans.