Petrified Wood - pretty much looks like a wood tree and not a stone tree.

 This is the only tree with the base still attached,  It was at least 6 foot across.

This tree was whole until the ground eroded away and the parts below rolled down in 2005.

 Here is a good cross section of a log.

Funny that when the tree turned to stone the hole did not fill up also.

 Here is a tall tree, it is strange that the pieces are all about the same size.

They put the support under this tree to keep it together.