The pronghorn (Antilocapra americana) in the upper Yellowstone drainage is one of the few populations that was not largely or entirely eliminated by the early 1900s. It was used to re-establish or supplement populations in several states during the first half of 20th century. The population expresses much of the genetic variation that was formerly widespread in the species, but is no longer present elsewhere and retains one of only two pronghorn migrations left in the greater Yellowstone region. However, its size and migration route are much diminished since the 19th century as a result of development and habitat fragmentation on its winter range north of the park.

Updated 7/23/10