In addition to having a diversity of small animals, Grand Teton and Yellowstone national parks are notable for their predator-prey complex of large mammals, including eight ungulate species (bighorn sheep, bison, elk, moose, mountain goats, mule deer, pronghorn, and white-tailed deer) and seven predators (black bears, Canadian lynx, coyotes, grizzly bears, mountain lions, wolverines, and wolves). Bighorn Canyon National Recreation Area is known for its native bighorn sheep as well the feral horses on the adjacent Pryor Mountains Wild Horse Range, one third of which is located within the park’s boundaries.

The National Park Service goal is to maintain the ecological processes that sustain these species and their habitats while monitoring the changes taking place in the species' abundance and distribution. Seasonal or migratory movements take many species across park boundaries where they are subject to different management policies and land use practices.