From a PBS Article (Photos are mine)
In Northern New Mexico, a range of mountains rises up from the high desert: a wild, rugged land of the Faraway Nearby. The volcanic Jemez are isolated from all other mountain ranges — an island in the sky, surrounded by a desert sea.
The center of the Jemez Mountains is a slumbering supervolcano that exploded more than one million years ago in massive eruptions, creating a plateau of volcanic ash welded into rock up to 900 feet deep. Through the millennia, water sliced through the plateau, cutting myriad canyons that open onto the Rio Grande, which flows south through a massive rift valley on the eastern edge of the Jemez. From the Rio to the heights of the Jemez, the land rises more than a mile in elevation, creating different zones of life as temperature drops and moisture climbs in the steep ascent from canyon floor to alpine peak.
Encompassed in this rise is Bandelier National Monument, which preserves the unique dwellings of the Ancestral Pueblo people who farmed in the canyons and on the plateaus for centuries. The human history of this region spans more than ten millennia, and the vestiges of the Ancestral Pueblo settlements can be seen in the canyon floor pueblos as well as cliff dwellings, explored by climbing ladders up to cavate openings. Much of the Jemez Mountains are public lands, including Bandelier, the Santa Fe National Forest and, at the center of the range, the Valles Caldera National Preserve, the heart of the giant volcano.