Preserving our Equine Heritage on Public Land Act - Provides for: (1) the continued preservation and use of pack and saddle stock animals on public land administered by the National Park Service, and Bureau of Land Management, the United States Fish and Wildlife Service, or the Forest Service on which there is a historical tradition of the use of pack and saddle stock animals; and (2) defining the term "historical tradition of the use of pack and saddle stock animals" for purposes of this Act.