Petrified Forest National Park

A high desert park in northeastern Arizona preserving one of the world's largest concentrations of petrified wood, formed when ancient trees were buried in volcanic ash and their organic material replaced by silica over 225 million years. The 28-mile park road passes through the Painted Desert in the north, with its bands of lavender, red, and white badlands, before descending to fossil log concentrations in the south. Crystal Forest and Giant Logs are among the most accessible sites.