The base of the tail, the "button", has degenerated to such an extent that the rattle immediately falls off with each shed instead of forming a new segment, as it does in other species of rattlesnakes.

This species also lacks the standard bite-and-release tactic employed by usual rattlesnakes, preferring to instead hold prey in its jaws until the venom can take effect.

Of the two distinct color variations, the predominant variant has a light cream-colored base, with reddish-brown blotching down the back, and black and white banding around the tail.

[1] This means that the best available evidence indicates it is considered to be facing an extremely high risk of extinction in the wild because its geographic range is estimated to be less than 100 km2 (39 sq mi), it exists at only a single location, and a continuing decline has been observed, inferred, or projected in the number of mature individuals.

[1] There is no guarantee that the cats will not be reintroduced into the area, which could cause problems for the snake, whether that be from being preyed on themselves or through the population decline of their main food sources.

[13] Climate also impacts the Santa Catalina by influencing plant productivity which is mostly related to the vast differences in the quantity of rainfall.

Bahía de Loreto National Park considered the rattlesnake as "very difficult to observe" which adds to the lack of conservation efforts.

Because this species is endemic to the island and the territory is fairly small, the area being 40.99 km2, the snakes are faced with possible inbreeding, demographic and environmental stochasticity, and more.

[5] It is believed that the snakes find shelter in the vegetation to help maintain a constant body temperature as well as use the density to hide from predators.

[9] While most members of this genus, Crotalus, are almost entirely terrestrial due to their heavy body structure, this species' small size makes it a swift and skillful climber.

Currently, the greater evidence supports the theory that the Santa Catalina rattlesnake has evolved away from having a rattle because it has no need for a warning mechanism against predators.

Previous theories [6] suggested the tendency for this rattlesnake to climb into low bushes was connected to a dietary shift toward consuming birds.

The restricted diet of the Santa Catalina Rattlesnake compared to its sister species is likely due to the limited prey diversity on the island.

[16] For example, the main prey is the endemic Santa Catalina Deer Mouse, Peromyscus slevini, which are measured to 21 cm (8.3 in) in total length including the tail, which is 10 centimeters (3.9 in).

However, a later study by Murphy and Crabtree (1985) used allozyme data to conclude the Santa Catalina rattlesnake shares its most recent ancestor with C. ruber.