Petrified Forest National Park is a surprising land of scenic wonders and fascinating science. The park is located in northeast Arizona and features one of the world’s largest and most colorful concentrations of petrified wood. Also included in the park is the multi-hued badlands of the Chinle Formation known as the Painted Desert, historic structures, archeological sites and displays of 225 million-year-old fossils. Petrified Forest National Park protects 93,533 acres, with a recently expanded boundary increasing the acreage to 218,533 acres.
On December 8, 1906, President Theodore Roosevelt set aside “selected forests” as Petrified Forest National Monument. In 1932, some 2,500 acres more of the Painted Desert were purchased and added to the Monument. On December 9, 1962, the area became Petrified Forest National Park and in 1970, 50,000 acres were further set aside as a wilderness area.
Introduction
Petrified Forest National Park in Northern Arizona lies on either side of Interstate 40 about 55 miles west of the New Mexico border and 25 miles east of Holbrook. It includes a grassland ecosystem and the badlands of the Painted Desert. The terrain changes quickly as you travel through the park, from the vistas of the Painted Desert, into the grassland of a large plateau, through grand geologic formations and arrays of richly colored petrified wood. Petrified Forest was set aside as a national monument in 1906 to preserve and protect the petrified wood for its scientific value. Petrified Forest National Park, since 1962, is now recognized as protecting the best representation of the Late Triassic Period in the world, significant archeological sites representing cultures during over 10,000 years of occupation, recent human history such as the Civilian Conservation Corps, Route 66 and historic architecture, as well as the natural ecosystems rapidly being lost in other areas.
Visitors can drive the 28 miles of the park road, stopping at any number of overlooks to see petrified wood, petroglyphs, archeological sites and Painted Desert vistas. Those with more time can explore the secrets of the backcountry. Permits are available for those visitors who wish to camp overnight.
History & Culture
Since earliest times, a well traveled east-west trade route has followed the Puerco River through this area of eastern Arizona. Ancient and prehistoric Indians, as well as explorers, hunters and pioneers, used the trade route to travel to Baja, California and the Pacific Coast. Later, the transcontinental railroad followed this route, then the transcontinental Highway U. S. Route 66 and today, Interstate 40 runs right through Petrified Forest National Park. Archeological sites throughout the Park reveal a human history in the area going back more than 2,000 years. Archeologists haven’t revealed the entire story, but there were separate occupations, a cultural transition from wandering families to settled agricultural villages, pueblos and trading ties with neighboring villages. Then this story of early peoples, told by potsherds, rubble and pictures on the rocks, fades about 1400 A. D.
The Puerco Ruins were occupied by the Anasazi twice, from 1100 to 1200 and 1300 to 1400 A. D., but Spanish explorers found no human habitation here when they arrived in 1540. Indian petroglyphs adorn Newspaper Rock and occur throughout the Park.
Nature & Science
Geology
The geology of Petrified Forest National Park is similar to many other parks of the Colorado Plateau. Erosional landforms, sculpted from flat rocks characteristic of arid regions, dominate the scenery. But here, embedded in the Chinle Shale formation, thousands of petrified logs appear in an array that is unsurpassed for variety and profusion anywhere else in the world. This high, dry tableland surrounding Petrified Forest National Park was once a vast floodplain crossed by many streams. To the south, tall, stately pine-like trees grew along the headwaters. Crocodile-like reptiles, giant fish-eating amphibians and small dinosaurs lived among a variety of ferns, cycads and other plants and animals that are known only as fossils today. The tall trees were washed by swollen streams into the floodplain.
There they were covered by silt, mud and volcanic ash and this blanket of deposits cut off oxygen and slowed the logs’ decay. Gradually silica-bearing ground waters seeped through the logs and, bit by bit, encased the original wood tissues with silica deposits. Slowly the process continued, the silica crystallized into the quartz and the logs were preserved as petrified wood. That was about 225 million years ago in the late Triassic Period. After that time, the area sank, was flooded and was covered with freshwater sediments. Later the area was lifted far above sea level and this uplift created stresses that cracked the giant logs. Still later, in recent geological time, wind and water wore away the gradually accumulated layers of hardened sediments. Now the petrified logs and fossilized animal and plant remains are exposed on the land’s surface and the Painted Desert has its present sculpted form.
Today, the ever present forces of wind and water continue to remove sediments. Erosion continues to break down the giant logs and expose the logs and other remaining fossils still buried below the surface. In some places, up to 300 feet of fossil-bearing material remains. The petrified logs, the other fossils of plants and creatures that lived in the area and the rocks locking them in place, all testify to changes in the environment through millions of years.
Ecology
Only a scant amount of vegetation grows among the deeply eroded soft clay hills of Petrified Forest National Park, but vegetation flourishes in the volcanic soils along the rim. Juniper and cliffrose are prevalent along the rim, as they are across much of the Colorado Plateau at this elevation of 5,500 feet.
Fossils of some of the earliest dinosaurs, strange giant reptiles, weird-looking plants and unusual fish have been found at Petrified Forest National Park since 1981. Nicknamed Gertie, one dinosaur discovered in 1984 continues to confound paleontologists, who are still looking for clues to her place in the family tree. Gertie’s bones eventually will be displayed at the Park. Supported by donations, fossil research continues to reveal life in Triassic forests of 225 million years ago.
Attractions
Painted Desert
This high, dry tableland was once a vast floodplain. Today, the forces of wind and water continue to remove sediments, break down the exposed logs and unearth the logs and other remaining fossils still buried below the surface. Up to 300 feet of fossil-bearing material remains in some places. The petrified logs, other fossils of plants and creatures that lived in the area and the rocks locking them in place all testify to changes in the environment over the course of millions of years.
Puerco Ridge/Rainbow Forest
Evidence of early human occupation is readily visible on the landscape. Sites throughout this region tell of human history in the area for more than 10,000 years, over the course of which there was a cultural transition from wandering families to settled agricultural villages - pueblos - and trading ties with surrounding villages. Although evidence of these early people fades around 1400 A. D., their story remains to be told through their dwellings, potshards and petroglyphs.
Puerco Pueblo
A 100-room pueblo built before A. D. 1400, partially stabilized. Petroglyphs can be viewed on the far side of pueblo.
Newspaper Rock
View large boulders covered with petroglyphs.
Tepees
Formations colored by iron, manganese and other minerals.
Jasper Forest Overlook
An excellent place to see many petrified logs strewn across the landscape.
Recreation
Petrified Forest National Park activities include the park film, museums, sightseeing, photography, walking, hiking and wilderness backpacking. A variety of ranger programs are given year round with an increased number during the summer. A program schedule is displayed at visitor contact areas.Note: The removal of petrified wood or other features of the park is prohibited by law. Gift shops sell petrified wood that comes from private land, outside the park. No petrified wood is removed legally from the park.
Driving non-stop, through Petrified Forest National Park, takes 45 minutes. The park is locked at night and visitors must be in their cars and driving towards an exit at closing time.
Getting There
Petrified Forest stretches between Interstate 40 and U. S. Highway 180.
From Interstate 40 West
Take exit 311, drive through the park and connect with U. S. Highway 180 at the south end.
From Interstate 40 East
Exit at Holbrook and take U. S. Highway 180 to the park’s south entrance.
Traveler Facts
Contact Information
Petrified Forest National Park
P. O. Box 2217
Petrified Forest National Park, AZ 86028
Phone: 928-524-6228
Operating Hours & Seasons
Petrified Forest National Park is open year round except Christmas - December 25. Park hours are 8:00 a.m. to 5:00 p.m., with extended hours during the summer. Hours may vary, so call before your arrival.
Note: Arizona does not observe Daylight Savings Time.
Weather/Climate
Summers are generally hot with temperatures in the 90’s and occasionally in the low 100’s F; night time lows are in the 50’s. In winter, the highs are in the 40’s or 50’s, or much colder with highs only in the 20’s. Annual rainfall is 9 to 10 inches with 40% occurring as thunderstorms in the late summer. There is occasional snow in the winter. High winds can occur any time of year. Humidity is usually low. Elevation is 5500 feet above sea level.
