Well, not exactly. Pronghorn antelope, as they are known throughout the mountain west, are not really antelope at all. The pronghorn is the only non-extinct member of its family which formerly consisted of 15 species. Giraffes are the closest existing relatives of pronghorns, but pronghorns are also related to deer and other ungulates. Pronghorns are the fastest land mammal in the Western Hemisphere, having been clocked at up to 55 miles per hour (hence none has every received a speeding ticket). In fact, worldwide only the cheetah is faster than the pronghorn, although pronghorns might win the race (and they better hope they do) because cheetahs have far less endurance at maximum speed.