Because lands administered by BLM’s St. George Field Office lie astride the transition between three major physiographic provinces including the Colorado Plateau, the Great Basin, and the Mojave Desert, Public lands support vast numbers of plant and wildlife species, many at the extreme end of their natural ranges. Elevations range from a low of 2200 feet at the Arizona border to nearly 10,400 feet in the Pine Valley Mountains. These features contribute to a rich biological diversity that is otherwise uncommon in parts of the arid, intermountain west. The diversity draws sportsmen, scientists, researchers, and wildlife watchers from across the North American continent to study, enjoy, or to engage in habitat improvement initiatives for the benefit of the species, many of which are listed as threatened or endangers under state and federal laws.