This large rattlesnake only occurs in the Mexican states of Oaxaca and Puebla in a variety of habitats including desert, mesquite grassland, and pine-oak forests. They are relatively calm and docile snakes, but their venom is not to be underestimated. Their diet primarily consists of small mammals and birds. The Oaxacan black-tailed rattlesnake can be quite variable in coloration, ranging from dark brown to golden yellow.

This subspecies used to be regarded as being under the Mexican west-coast rattlesnake (Crotalus basilicus)--the morphological similarities are very close! However, genetics placed this subspecies where it currently stands today under the western black-tailed rattlesnake (Crotalus molossus).