Beaver, beavers, North American Beaver, North American Beavers, american beaver, american beavers, Castor canadensis, mammal, mammals, animals, rodents, wildlife, animal, fauna, rodent, aquatic, wetland, wetlands, wetlands wildlife, wetland wildlife, pond, lake, riparian, river, water, North America, Western U.S., Wyoming, Montana, Yellowstone, Yellowstone National Park, horizontal, dam, dam building, build, building, work, working, mud, behavior