Gary and Brenda's California Trip

California
San Francisco, Yosemite National Park, Muir Woods, Napa and Sonoma Valley, and some Coast

DAY 7, Part 2: The Napa Valley Petrified Forest

petrified tree

There is a petrified forest in the Napa Valley between Santa Rosa and Callistoga. There was a forest in this area about 3.4 million years ago when a nearby volcano, Mt. St. Helena, blew up. The trees were mown down, and they are all lined up -- pointing away from the volcano. They were composed of quite a few very large redwoods. When they turned into petrified trees, they became the largest petrified trees in the world. The way they became petrified was described to us. First they were covered in volcanic ash. Then they were covered by water which leeched down through the ash and carried the minerals that eventually became the stone you see in these pictures. We were told that there was at times a one-for-one exchange of molecules or cells. Sometimes, when you look at the rock, you can see the rings of the trees. The age of many of the trees at the time they fell can be estimated. Then the stone continued to harden as sediment covered the area at the bottom of the water. Later the sediment was washed away, revealing parts of some of the petrified trees. They were then dug out of the earth. Of course, they are left on the spot where they are found. These are pictures of some of the trees which have been dug out. There are an unknown number of trees yet to be dug out.

petrified tree
The end of one of the trees. It sure looks like a fallen tree, but it is rock.

You can see the roots of this petrified tree.

petrified tree

This is a composite of six pictures. I apologize for the quality. I was walking down along the side of the tree snapping pictures. I wasn't careful about how far I was from the tree, and the affects of the amount of sun at each spot makes each part of the picture have a different exposure so that it doesn't look very good. I put them together to give you an idea of how large these trees are.