The boreal toad (Anaxyrus boreas boreas) is a subspecies of the western toad (Anaxyrus boreas). They are commonly found in the Southern Rocky Mountains and in recent, their population has been on the decline due to an emerging amphibian disease, chytrid fungus. The boreal toad is currently listed as an endangered species by Colorado and New Mexico. It is known in Colorado as the only alpine species of toad.