arizona petrified trees
Thomas Nelson
Thomas Nelson
April 7, 2020 ·  3 min read

Arizona Is Home To Ancient, 200 Million-Year-Old Trees, Some Of The World’s Oldest!

Arizona is, to borrow from the neighboring state of New Mexico, a land of enchantment. The southwestern U.S. state is home to the meteor crater, Grand Canyon National Park, Monument Valley, Saguaro National Park, and the focus of this article: Petrified Forest National Park.

In a way, Petrified Forest National Park has been with me my entire life. Years before I was born, my father obtained a piece of polished petrified wood from the park. I remember being a child and my dad telling me to count the rings and teaching me that each of those rings represented one year of the tree’s life. He’s no longer with us, but I still have that piece of petrified wood sitting on my desk as I write.

Petrified Forest National Park is one of my favorite places in the world, and I think when you’re done reading, you’ll understand why.

Petrified Forest National Park is an American national park located in Northeastern Arizona. It was named for, you guessed it, a rich deposit of petrified wood. The Park is a total of 230 square miles stretching through Navajo and Apache counties. [1]

Read: Ancient tree with record of Earth’s magnetic field reversal in its rings discovered

Petrified Forest National Park was first declared a national monument in 1906. In 1962, President John F. Kennedy used powers granted to him by the Antiquities Act to designate the 230 square mile section of Arizona a national park. The Antiquities Act of 1906 allows Presidents to proclaim national monuments on federal lands if they contain historic landmarks as well as historic or pre-historic structures or other objects of historic or scientific interest. [2]

Petrified Forest National Park is well known for its fossils, particularly from a period approximately 225 million years ago during the Late Triassic Epoch. At that time, what is now modern-day Arizona was situated near the equator of Pangaea. Like many places near the equator today, the climate was tropical. Many organisms, some as large as trees, became fossilized and buried in organic matter.

Petrified wood is formed the same way as other fossils are. These fossilized trees at one point fell and were buried by sediment, which stopped them from decaying. [3] Groundwater rich in silica, calcite, pyrite, and other inorganic materials flowed through the sediment and slowly replaced the organic plant matter. These inorganic materials preserve the organic structure of the trees, even allowing us to see details in the bark and count the rings of these ancient trees.

The reason we’re able to easily see the petrified forest is because about 60 million years ago, tectonic movement began uplifting the Colorado Plateau, pushing parts of it to over 10,000 feet in altitude. Slowly, the plateau began eroding, revealing the petrified wood and other fossils from 200 million years ago.

Petrified wood isn’t the only attraction that can be found in the national park. It’s also home to over 600 archaeological sites. [4] These archaeological sites indicate that human beings first inhabited this area of the American southwest around 13,000 years ago. These ancient people built pueblos, sometimes out of petrified wood. One in particular, called Puerco Pueblo, may have been home to as many as 200 people. It’s also possible to see 650 petroglyphs made by pueblo people over the course of several centuries.

Petrified National Park is open every day of the year except for Christmas, although it is worth noting that the coronavirus pandemic has impacted the availability of some national parks in the U.S., so call ahead before you plan to visit. There are a total of 15 main hiking trails through the park, 7 of which are maintained. [5] Campgrounds and overnight lodging are not available in the park and overnight camping is strictly prohibited unless you are a backpacker with a wilderness hiking permit.

Keep Reading: Opalized Petrified Wood