Escalante Petrified Forest State Park, Utah

Hike among fossilized logs that were once towering conifers, buried in mud some 135 to 155 million years ago and slowly turned to stone as silica replaced their wood grain by grain. The mile-long Petrified Forest Trail climbs to viewpoints over Wide Hollow Reservoir, where you can also swim, paddle, or camp along the shore. Stop by the visitor center to see a 50-foot petrified log unearthed nearby from the Morrison Formation.