Rocky Mountain Elk, Rocky Mountain elk bull, rocky mt. elk, Elk, elks, wapiti, Cervus elaphus, animal, animals, mammals, ungulates, hoofed, hoofed mammal, mammal, wildlife, fauna, herbivore, ungulate, bull, male, antlers, rack, North America, Rocky Mountains, Wyoming, montana, Yellowstone National Park, yellowstone, winter, snow, survival, cold, vertical, bull elk, leesonphoto