Why it%27s a national treasure and the last one standing%3A No other ecosystem in the Lower 48%2C beyond Greater Yellowstone%2C still has healthy populations of all of these animals. While national parks provide habitat%2C these species cannot continue to persist based on terrain in parks alone%3B in fact%2C 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