Why it's a national treasure and the last one standing: No other ecosystem in the Lower 48, beyond Greater Yellowstone, still has healthy populations of all of these animals.  While national parks  provide habitat, these species cannot continue to persist based on terrain in parks alone; in fact, studies show that fragmentation caused by human pressure beyond park boundaries jeopardizes the ability of these animals to persist in viable numbers. Graphic courtesy NPS
Why it's a national treasure and the last one standing: No other ecosystem in the Lower 48, beyond Greater Yellowstone, still has healthy populations of all of these animals. While national parks provide habitat, these species cannot continue to persist based on terrain in parks alone; in fact, studies show that fragmentation caused by human pressure beyond park boundaries jeopardizes the ability of these animals to persist in viable numbers. Graphic courtesy NPS