Sunset Crater was created by a series of volcanic eruptions between 1040 and 1100 that brought the dormant San Francisco Peaks volcanic field back to life. The eruptions created a fire fountain, spewed ash and cinders into the sky, and sent a slow-moving lava stream across the ground, where it started forest fires.
Native Americans living in pit houses in the area, known as the Sinagua, fled the deafeningly loud, highly destructive conflagration, with some relocating to nearby Walnut Canyon and Wupatki. The eruption left a 1,000-foot cinder cone where forests and meadows had once been.
The Sunset Crater Volcano National Monument protects 3,040 acres with the youngest, least-eroded cinder cone in the volcanic region. The stark landscape looks like it’s from another world, covered with lava flows and deep volcanic cinder deposits. But it is becoming dotted with vegetation as pine and aspen trees, desert shrubs, and wildflowers gain a foothold, along with wildlife.
The most popular way to explore the monument is the Lava Flow Trail, an easy one-mile loop trail with a quarter-mile wheelchair-accessible loop that takes visitors through the dried lava flows and volcanic cinder deposits. A second, strenuous hike, on the Lenox Crater Trail, takes visitors on a steep climb up cinder-covered slops to the top of a cone. The Lenox trail is one mile round-trip.
The monument also has a visitors center with exhibits on the volcano and ranger talks and guided hikes. It is located 12 miles north of Flagstaff off U.S. 89.