This video shows the benefits realized by the reintroduction of the American Beaver to the San Pedro River of Southern Arizona as a keystone species for the improvement of the environment and quality of life for other animals. The video considers the reintroduction of elk and moose in the states of Colorado and New Mexico and how these animals benefit from the presence of the beaver in those areas. Beaver diet and lodges are compared and contrasted in the three states. Video features exceptional footage of many animals and landscapes of the Southwest.