You can see that we are hiking the old road through the forest that once existed so long ago, I can't even fathom.

Special rare conditions must be met in order for...fallen [trees] to be transformed into...petrified wood. In general, the fallen [trees] get buried in an environment free of oxygen (anaerobic environment), which preserves the original plant structure and general appearance. The other conditions [needed are] mineral rich water in contact with the [trees], replacing the organic plant structure with inorganic minerals [such as quartz].