The Petrified Forest is pet-friendly. The forest was created after Mount. St. Helena (seen from the Silverado Trail) erupted 3.4 million years ago and engulfed a redwood forest in volcanic ash, preventing decay and preserving the trees. It wasn’t until 1870 that the forest was discovered underneath a pasture and became a point of interest for paleontologists. These days, visitors and their dogs can take to the trails of the forest and enjoy the natural phenomenon together. The Petrified Forest is open every day of the week from 9am to 6pm.