This medium-sized rattlesnake averages about 2-3.5 ft in length. It inhabits southern California, Arizona, and the southern tips of Nevada and Utah. Southwestern Speckled rattlesnakes typically inhabit higher elevations, preferring rocky slopes and outcroppings in high arid environments.

This species is highly variable in coloration from pink to blue to black-and-white; varying almost entirely in relation to the shade of rocks in where they are found, such that populations from grey rocks are darker grey, red rocks are more pinkish/terra-cotta and lighter rocks are almost white. This color variation helps them to blend in better with their environment, advantageous for both avoiding predators and ambushing prey.

Fun fact: Crotalus pyrrhus has been observed using its body to collect drops of rain during limited desert precipitation events, which they then drink. This behavior is known as "rain harvesting", and helps the snake to survive in extreme environments.