As one of the rarest rattlesnakes in the world due to its limited range and the difficult terrain it occupies, everything about this rattlesnake is a fun fact! The Sinaloan long-tailed rattlesnake was first known to science in 1897.

This relatively small rattlesnake is found in western Mexico in forested habitat along the Sierra Madre Occidental. Its long tail can be up to 14.8% of its total body length with males having longer tails than females on average.

This rattlesnake is classified as Vulnerable by the IUCN primarily due to its restricted range. It is only known from around 12 collected specimens.