The natural world of Petrified Forest is far more complex than it seems on the surface. Located near the southern edge of the Colorado Plateau, the park is part of an amazing geological region. Some of the most famous geological parks are found on the Colorado Plateau, including Grand Canyon, Zion, Bryce, and Arches—just to name a few. Each has its own character, including which layer of the geological story is featured by that park. Petrified Forest has two geological formations, the Late Triassic Chinle Formation and the Mio-Pliocene Bidahochi Formation. Ancient environments are represented by these layers. The fossils that are found here help scientists reconstruct those ancient environments.