Petrified Forest

Petrified Forest National Park is located in Navajo and Apache counties in northeastern Arizona. The park’s headquarters are about 26 miles east of Holbrook along Interstate 40. Named for its large deposits of petrified wood, the park covers about 146 square miles. Petrified Forest National Park encompasses semi-desert shrub steppe as well as highly eroded and colorful badlands.

The Petrified Forest is known for its fossils, especially fallen trees that lived in the Late Triassic, about 225 million years ago. The sediments containing the fossil logs are part of the widespread and colorful Chinle Formation, from which the Painted Desert gets its name. Beginning about 60 million years ago, the Colorado Plateau, of which the park is a part of, was pushed upward by tectonic forces and exposed to increased erosion. All of the park’s rock layers above the Chinle, except geologically recent ones found in parts of the park, have been removed by wind and water.

Paleontologists have been unearthing and studying the park’s fossils since the early 20th century. In addition to petrified logs, fossils found in the park include Late Triassic ferns, cycads, ginkgoes, and many other plants. Fossils of giant reptiles called phytosaurs, large amphibians, and early dinosaurs have also been found.

Scientific studies are on-going at the park. Paleontologists find new fossils, including new species of plants and animals, each year. Biologists study living plants and animals, including vegetation surveys and reptile, amphibian, and mammal projects. Air quality, weather, and seismic monitoring stations constantly generate new data.

Petrified Forest was set aside as a national monument in 1906 to preserve and protect the petrified wood for its scientific value. It is recognized today for having so much more, including a broad representation of the Late Triassic paleo-ecosystem, significant human history, clear night skies, fragile grasslands ecosystem, and unspoiled scenic vistas.

Go to the Petrified National Forest Park Website for more information on this natural wonder.