Arizona's most popular natural wonders include the Grand Canyon, Havasu Canyon, Grand Canyon Caves, Lake Powell/Rainbow Bridge, Petrified Forest/Painted Desert, Monument Valley, Sunset Crater, Meteor Crater, Sedona Oak Creek Canyon, Salt River Canyon, Superstition Mountains, Picacho Peak State Park, Saguaro National Park, Chiricahua National Monument, and the Colorado River. Oh! and don't forget the reconstructed London Bridge at Lake Havasu City! Today some 18 million tourists a year visit the state, two million of whom are (not counting bleepin' snowbirds) visitors from other countries. I was trying to decide between doing a write up about the Grand Canyon National Monument or the Petrified Forest National Park. My husband said Do the one about the Petrified Forest! Nobody knows about it, most people have not even have heard of it I would even bet you 90% of the people in the United States have even ever heard of it. It might even be higher than that! Most people in Arizona haven't heard of it! Well that may be a bit exaggerated but when we visited it there weren't very many people. Certainly fewer that the over crowded Grand Canyon but just as breathtakingly beautiful! It was surprising to learn that over a million people visit the park annually with peak visitations occurring in the summer months.

President Teddy Roosevelt signed the proclamation making the 93,532.57 acre forest a national monument on December 8, 1906. In 1962 congress made it a national park. It's a Rock hound's Paradise! Did you know that the movie The Painted Desert starring Clark Gable and William Boyd was filmed at the park in 1931 and five years later Betty Davis and Humphrey Bogart made another movie called what else? The Petrified Forest! And guess what? Petrified wood (Araucarioxylon arizonicum) is the official state fossil of Arizona! Most petrified wood comes from the Petrified Forest right here in the Mojave Desert.

I visited there as a little girl and remember wanting to pick up a piece of petrified wood as a keepsake. Thankfully today people are prevented from picking them up, if everyone did that pretty soon there wouldn't be a Petrified Forest anymore. In the early 1900's, so many were removing the the wood from the area that this led to calls for preserving areas with large deposits of it. The park exists for this purpose and there is no collecting or giving out of samples permitted. Dad bought me one from a commercial dealer who do their collecting outside the park. Many artisans collect and make beautiful objects with them. It wasn't until April 2001 that it was removed from the National Parks Conservation Association top ten most-threatened list. In the early days of the park, tourists were constantly taking logs from the desert floor to keep as souvenirs. They were removing 12 tons of petrified wood each year in violation of federal law. Don't take any of the wood, not even a small piece because you just might regret it. Make sure to visit the Rainbow Forest Museum before you leave. Along with the exhibits they have what is referred to as "conscience letters" displayed on the wall. These are from people who have stolen petrified wood from the park and feel obligated to return it, sometimes even sixty years later. One man made a bolo tie (the official state tie of Arizona) from his stolen petrified wood, and he returned it in its altered state. Another woman smuggled three pieces out of the park in her bra, returned two of them (keeping one to remind her of her mistake) AND sent $0.20 for the park to buy more petrified wood--from whom, I don't know.

Within the Petrified Forest National Park is The Painted Desert also called the Chinle Formation of the Late Triassic Period composed of wonderful colorations and hues. On top if that there are several archeological sites and displays of 225 million-year-old fossils in an expanse of badland hills, flat-topped mesas and buttes. The land is arid, heavily eroded by the desert winds and has very little vegetation.

    The landforms of the Painted Desert have been described as a multicolored layer cake. The variety of hues in the sandstone and mudstone layers of the Chinle Formation is the result of the varying mineral content in the sediments and the rate at which the sediments were laid down. When sediments are deposited slowly, oxides of iron and (hematite) aluminum become concentrated in the soil. These concentrations create the red, orange, and pink colors you see at the north end of the park. During a rapid sediment buildup such as a flooding event, oxygen is removed from the soil forming the blue, gray, and lavender layers.
You weren't expecting petrified trees where petrified birds perch singing petrified songs were you? You can feast your eyes on the multihued sandstone battlements abruptly raising from the vibrant sandy sea. Row upon row of silty-gray mounds emerge from the earth split by layers of pink, orange, mauve, and purple sediments that change color with every angle of the sun or drifting cloud. Here and there, the hillsides are adorned with brick red colored boulders the size of box cars. And, scattered about plain and hillside alike are the remains of broken fossilized trees that give the park its name. It's a land that time forgot, but now, through tectonics and erosion, has exposed itself again.

Most of the trees today are lying about in broken sections of various sizes. The Agate Bridge, which is really a petrified tree and not related at all to the London Bridge in any way, is the largest specimen. But watch out for hoodoo's! A geomorphologist paraphrases the Apache legend about how the Creator let loose a great Deluge when He was upset with the earth and decided to start over. He favored the Apache, and was willing to give them shelter. However, a group of greedy and evil men took advantage, and rushed up to the hills without helping the young, the elders, and the women from the approaching flood. The Creator was so angered with them, that He punished them by turning them into stone as they stood on the ridges. Thus, the hoodoos are the petrified men who abandoned their tribe. Who do I think I'm fooling! It sounds a lot like the biblical story of Noah and the flood doesn't it? Actually they are formed when a hard top crust of sediment is eroded in areas exposing the soft rock underneath which then erodes rapidly. The hard crust remains in parts protecting the soft rock underneath and forms a pillar, or a hoodoo. Some of them are quite large. Hoodoos are common in areas of badland , the most well known are found in Bryce Canyon National Park. There are a few that lurk around the Petrified Forest too, only the "cap rock" on the hoodoos is petrified wood. These are entombed in the soft, easily eroded Chinle Formations. The petrified logs and stumps, protect the underlying rock, producing some very elongated and somewhat squat hoodoos.

At one time the area was a great floodland with large copses of trees like Araucarioxylon, Woodworthia and Schilderia that fell during the frequent flooding and washed down stream where they were covered by silt, mud, and volcanic ash. Sealed in the airless tombs the log decayed slowly and eventually ground water containing silica seeped in surrounding the tissue of the wood and crystallized into mineral quartz preserving the tree as petrified wood. That was about 225 million years ago during the late Triassic period. After that the land sank where it flooded with freshwater and covered with sediments. Later the land was lifted above sea level and the wind and rain eroded the now stressed and fractured trees leaving them exposed on the terrain along with other fossilized animal and plant remains

Petrification occurs when the tissue of ancient trees become complexly replaced by minerals. This is called permineralization. When the branches and trunks become stone, details of ancient plants become quite remarkable. Sometimes when they are preserved in amber the cell structure is protected so perfectly that DNA fragments within them can be extracted and sequenced.

The area was mapped by the United States Army in the mid 1800's and soon word spread about trees that had turned to stone and the beautiful Painted Desert. Archeologists have discovered that the area has been inhabited by humans for well over two thousand years. There were several individual occupations with potsherds, rubble, and pictures that tell a story of transitions from nomadic families to agricultural settlements, pueblos and trading with nearby villages until 1400 AD when these civilizations all seem to fade away.

There are literally thousands of petroglyphs and pictographs scattered around the American southwest. Newspaper Rock in the Petrified Forest an interesting example. It's the name given to a huge boulder that is covered with these drawings by ancient Indian tribes. Even though the rock itself is at the bottom of a cliff and hard to access on foot, the petroglyphs are easily seen using binoculars. Patterns of circles and images of animals are etched or painted onto the rocks for reasons archeologists aren't completely sure yet but studies have revealed a few clues.. It's known that around the time that Francisco Vásquez Coronado came through Arizona in the mid fifteen hundreds the area was pretty much uninhabited. However only a few hundred years earlier there were a group of people who belonged to the Ancestral Pueblo People that farmed the area and occupied up to 600 known sites in the Petrified Forest. One scientist, Bob Preston has spent the last two decades studying the sites and the images left behind. He is convinced that many of them were used as a solar calender and function much the same way today as they did years ago by tracking the sun across the sky through the interplay of sunlight on the petroglyph. Over the last 16 years he has identified about 120 examples of similar solstice events at more than 50 petroglyph sites in Arizona, New Mexico and southern Utah. He calls them "solar observatories." One web site explains how they work:

    In 1977 a spiral petroglyph at Chaco Canyon National Monument was discovered which displayed a precise interaction with sunlight at the time of summer solstice by means of a narrow shaft of sunlight that moved down a shadowed rock face to bisect the center of a large spiral petroglyph. Subsequent observations found that on winter solstice and equinoxes there were intriguing interactions of sunlit shafts with the large spiral and a smaller spiral nearby. No other example of a sunlight interaction with prehistoric or historic petroglyphs was known at this time. However, there was a tradition of Pueblo sun watching in historic times, particularly of the varying sunrise and sunset positions throughout the year, to set the dates for ceremonies.

    Shadows and sunlit images are found to move across petroglyphs due to other rocks being in the path of the sun's rays. As the sun's path across the sky changes throughout the year, the positions of the shadows and sunlit images change on the petroglyph panels. In many cases the petroglyphs have been placed on the rock faces in just the right position so that specific interactions occur on the solstices. The most common types of petroglyphs on which solsitial interactions have been identified are spirals and circles.These consistent interactions may involve a point of sunlight or shadow piercing the center or tracing the edge of a spiral or circular petroglyph; or shadow lines may suddenly appear or disappear at the center or edges of the petroglyph; or they may move up to the center or edge and then retreat. It is not uncommon for a single petroglyph to display multiple interactions of this type, either on the same solstice or on each of the solstices. In fact, at one site, there are five circular and spiral petroglyphs that show 15 interactions on the both solstices.

How fascinating! Archeology and astronomy all rolled into one. A small window into the ancient peoples of the desert as they watched these slow motion movies through the seasons. To make a petroglyph they would look for a rock covered with what is called "desert varnish." The surface of the rock is dark and when scratched the lighter rock underneath created a contrasting image. The varnish on the rock is caused over a long period of time becoming a filmy layer of organic components made mostly out of a thin coating of iron or manganese, and bacteria. These petroglyphic images have been classified into six categories: anthropomorphs, zoomorphs, kachinas, hands\tracks, geometrics, and indeterminate.
  • Anthropomorphs and Kachinas represent the human form. Anthropomorphic figures may have complete bodies but generally lack facial features. Kachinas often take the form of heads or masks and most have facial features.
  • Zoomorphs include large and small animals, reptiles, and birds. Look closely and you will see cougars, birds, lizards, snakes, bats, coyotes, and rabbits on petroglyph panels at Petrified Forest.
  • Hands and tracks include bear paws, bird tracks, cloven hooves and human feet or hand prints. Some human tracks even appear in pairs.
  • Geometrics consist of textile and pottery designs, spirals, circles, and other geometric shapes. You will see many of these elements at Puerco Pueblo and Newspaper Rock.
  • Indeterminates may be simple doodles or might be a picture to commemorate a special event in a life or the community.

Paleontologists are slowly reconstructing the Triassic ecosystem by piecing together fossil records. The creatures that wandered the vast forest of the period were crocodile-like reptiles, giant fish-eating amphibians and small dinosaurs living among a variety of ferns and cycads. Exhibits in the Rainbow Forest Museum at the park include freestanding casts of some Triassic Period reptiles and displays on early dinosaurs.

  • Placerias was a large, bulky plant-eating reptile weighing up to 2 tons. It had strong but toothless jaws and probably lived on a diet of tough, fibrous plants. The large tusks may have been used to dig up roots and tubers for food. Belonging to a group known as phytosaurs, fossils indicate that some individuals reached 30 feet in length. They lived a crocodile-like life in the rivers and lakes preying on fish and smaller animals. Bony plates protected the body and tail.
  • Desmatosuchas was a 16-foot long, plant-eating reptile that sported a long, pig like snout and looked like an overgrown armadillo. A bony carapace (shell) covered the long narrow body and large spikes on its sides were probably used for defense.
  • Chindesaurus was an early primitive dinosaur. It was 8 to 12 feet long from head to tail, with sharp, sickle-shaped teeth indicating a meat diet. Lightly built with exceptionally long hind legs, it may have been one of the fastest land-dwellers in this area. This speed helped it overtake its prey.
  • Coelophysis was one of the early known dinosaurs. It was about 8 feet long and could weigh 50 pounds. Long slender jaws lined with sharp, flattened teeth indicate it was carnivorous. This agile animal probably walked on its hind limbs and used its forelimbs to catch and hold prey. Large eye sockets suggest keen eyesight. This ferocious looking reptile was a large land-dwelling predator. It moved in a dinosaur-like way with its legs tucked under its body not sprawled out to the side like most reptiles. A medium sized animal was about 13 feet long.
There are no established trails so hiking is a cross country trek. The weather ranges from the 90's to low 100's during the day to the 30's and 40's at night. There are summer time thunderstorms and the possibility of flash floods so check the weather. It's a wide open range and perfect for cross county hiking. With rabies and hantavirus it's best to avoid contact with any animals living or dead. For you herpatologist fans the petrified forest is also home to the milk snake (Lampropeltis triangulum taylori), Arizona's rarest snake. If you come across a fossil leave it in place and report it to one of the rangers. It's a piece to a giant puzzle of time for documanting and studied for clues to the past in this fascinating area. Make sure to bring enough water at least a gallon per person on hot days and wear a wide brimmed hat with long sleeves since there is almost no shade. Watch out for poisonous desert dwellers too! Look but don't touch. Make sure to check crevasses and under shady rocks for any critters before putting your hands in there or sitting down for a rest. Shaking out clothing will help avoid scorpions, spiders, and centipedes. Overnight camping is free but a permit is required. Only back pack wilderness camping is allowed but there are campsites outside the park.

How to get there:

The Petrified Forest National Park is located in east central Arizona near Holbrook, (the land of petrified everything for sale), a 27 mile road runs through the Park, from the I-40 exit number 311 to US 180. Open from 8am to 5pm every day except Christmas. No reservations are needed and fees range for a five days pass from five dollars for hikers and bikers to ten dollars for private vehicles.



Petrified National Forest:

Submitted in conjunction with the U.S. National Parks and Monuments

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