Petrified Forest National Park
Situated in east-central Arizona, Petrified Forest National Park began as a National Monument to preserve geologic resources, including petrified wood, from the Triassic Period. At later times, the park unit was expanded to include cultural resources and was designated a park. Among the archeological resources present are the Puerco Ruins, which date from near the end of the Pueblo period (~1100 A.D.). In addition to the petrified wood in the park, are fossils of leaves, invertebrates (e.g., snails and insects), vertebrates, such as giant amphibians, large crocodile-like reptiles, and early dinosaurs, and footprints. Three distinct geographic areas, Painted Desert, Puerco River Valley, and Rainbow Forest, comprise the park.