Visitors reach Orange Spring Mound via the upper terrace loop drive at Mammoth Hot Springs. The eye popping feature is colored by streaks of bacteria and algae. Mammoth Hot Springs Terraces, Yellowstone National Park. Yellowstone National Park, the first National Park in the world, still enthrals over three million visitors a year with it's geothermal features,wildlife, rugged mountains, deep canyons and stunning ecosystem.