The Rocky Mountain goat (Oreamnos americanus) may be as much antelope as it is goat. Mountain goats belong to an order of even-toed ungulates known as Artiodactyla. This large mammalian group includes antelopes, gazelles, cattle, muskox and true goats. Classified within the subfamily Caprinae or goat-antelopes, the mountain goat is the only member of the genus Oreamnos. The evolutionary history of this species is unclear, making the mountain goat a classic example of a ‘rogue taxon.’ Various DNA comparisons fail to link mountain goats with any one extant (living) Caprinae species thus suggesting that it is basal within its group. This distinction makes the mountain goat truly unique member of its biological family.