American Bison bulls, bison, American bison, buffalo, Bison bison, mammal, mammals, animals, animal, wildlife, fauna, ungulate, prairie, plains, grassland, bull, buls, males, fight, aggressive, aggression, conflict, behavior, sparring, dominance behavior, plains, grasslands, prairie, National Bison Refuge, National Bison Range, Bison Range, Bison Refuge, National Wildlife Refuge, National Bison Range Wildlife Refuge, Bison Range NWR, Bison Range National Wildlife Refuge, Montana, North America, horizontal, leesonphoto