Thursday we went to the Petrified Forest National Park and the Painted Desert. The Petrified Forest National Park is contained within the Painted Desert. The Painted Desert is several hundred miles long and stretches from Holbrook, Arizona in the east (where the Petrified Forest is located) all the way to the Grand Canyon in the west. The petrified trees are mindboggingly old - 216 Million years! That is back in the time of Pangea when the world was made up of one continent and dinosaurs were just beginning their reign. During the Pangea period, the area we now know as Arizona was a tropical rain forest much closer to the equator than it is now. In a nutshell, these trees fell into a river and were covered with silt. The wood absorbed the mineral laden ground waters and was eventually replaced by silica and other minerals. Millions of years later, through erosion, the trees became visible. 
A small section of petrified tree
Most of the logs are very colorful as a result of the different types of minerals they absorbed
Several log pieces where they fell 200+ million years ago
Some of the logs are enormous - this one is over 6 feet in diameter - there are some that are over 10 feet in diameter
Another fallen giant
The Painted Desert
The distinctive layers of color were formed over millions of years from changes in river deposits, climate and topography. This area of the desert has mostly hues of blue, grey and purple while other areas have reds, pinks, and oranges. The immensity and the colors of this place are difficult to capture in a snapshot - you have to see it in person.
Some of the dots on the valley floor are petrified log pieces
The "Blue Mesa" trail down to the canyon floor - well worth the strenuous hike back out
There are many 800 to 1000 year old sites of ancient civilizations in the desert - the following are some of the pyroglyphs we saw - this site was named "Newspaper Rock".
Nearby Puerco Pueblo remains - a pueblo of over 100 rooms dating back to 1200 AD. Only a portion is currently visible - much of it was excavated by archaeologists and then recovered to protect it.
Some of the reddish and pinkish formations
