Pull over where State Route 4 opens onto the Valle Grande and the first reaction is usually silence. The meadow in front of you is the floor of a volcano, a vast grassy bowl some thirteen miles across, ringed by forested domes and ridges, with elk grazing in the distance and the sky arching over it all. About 1.25 million years ago a colossal eruption emptied a magma chamber here, and the ground collapsed into the void, leaving a caldera. The ash from that blast settled into the pale tuff that forms the cliffs of Bandelier and the Pajarito Plateau nearby.
Later eruptions raised lava domes inside the bowl, and Redondo Peak, the largest, stands in the middle like a green shoulder. Hot springs, fumaroles and rich, deep grassland lie within. For years the land was a private ranch, and it passed to the public in 2000 as a national preserve. Elk are the stars, with big herds and a bugling rut in the early autumn, and prairie dogs, coyotes and hawks are easy to spot. Streams run clear in the folds, and trout swim in some of them. The altitude is well above eight thousand feet, so the air is thin, clear and cool even in summer.
The road along the southern rim is a pleasure. It curves gently across the meadow edge, rises through ponderosa and aspen and gives wide views over open grass. Traffic is moderate, the surface is generally smooth, and the corners are easy. Weather turns quickly at this height, with afternoon thunderstorms in July and August, snow in winter and cold nights even in early summer. Mornings are best, when mist hangs on the grass and the elk are close to the road.
The visitor area has water and restrooms, and entry has a fee that is easy to pay. Bring warm clothes and binoculars, and give yourself time to stand and look.