It may look arid and the landscape is crumbly, but according to the National Park Service, "During the Pliocene, this place looked quite different. Lush wetlands, forests, and grasslands provided excellent habitat for a variety of animals. From fascinating, now-extinct creatures like the saber-toothed cat, mastodon, and ground sloth, to more familiar animals like horses, beavers, and birds, the scientific study of Pliocene fossils is the key to Hagerman."