This description is about the Pronghorn, a species of antelope native to North America. It is the only surviving species of the family Antilocapridae, and is the fastest land mammal in the Western Hemisphere. This species is found in the western United States and Canada
From Wikipedia
The pronghorn is a species of artiodactyl mammal indigenous to interior western and central North America. Though not an antelope, it is known colloquially in North America as the American antelope, prong buck, pronghorn antelope, and prairie antelope, because it closely resembles the antelopes of the Old World and fills a similar ecological niche due to parallel evolution. It is the only surviving member of the family Antilocapridae.