Petrified Forest National Park is the kind of place that sneaks up on you. As you cruise at a brisk 80 miles an hour along Highway 40 in Arizona, a sea of sage, rabbitbush and grass stretches from the road’s shoulder to the horizon. This cloaking makes the transformation all the more dramatic once you reach the park. Not far inside the gate, the low scrub opens into the reds, blues and grays of the Painted Desert.