Crotalus mitchellii muertensis is a venomous pitviper subspecies[4][5] endemic to El Muerto Island, Mexico.

[1] A dwarfed form, adults grow to a maximum length of 63.7 centimetres (25.1 in).

[3] Known only from the type locality,[3] which is "El Muerto Island, Gulf of California, Mexico.

"[2] It is common in all habitats within the El Muerto Island: rocks and rubble of talus slopes, scrub, hill ridges, and the intertidal zone.

[1] Species are listed as such due to their wide distribution, presumed large population, or because it is unlikely to be declining fast enough to qualify for listing in a more threatened category.