gray wolf, gray wolf howling, gray wolves, timber wolf, timber wolves, wild gray wolf, wild gray wolves, wolf, wolves, grey wolf, Canis lupus, mammal, mammals, animals, animal, wildlife, fauna, canine, predator, predators, carnivore, howling, howl, communicate, communication, calling, voice, sound, fall color, fall, autumn, aspen tree, North America, Montana, captive, vertical, photo, photos, photograph, photographs, image, images, picture, pictures, stock, of, agency, leesonphoto