Sunset Crater National Monument was established by President Herbert Hoover on May 26, 1930, to protect its geologic formations. In 1990 the name was changed to Sunset Crater Volcano National Monument. It occupies 3,040 acres surrounded by Coconino National Forest.

Sometime between 1040 and 1100, a series of eruptions—the only eruptions in the Southwest indisputably witnessed by local peoples — brought the dormant San Francisco Volcanic Field back to life. Earthquakes, thunderclaps, and firebombs shook the ground. Billowing ash, falling cinders, and forest fires blackened both the landscape and the daytime sky, while at night, the horizon glowed fiery red. When the field again grew quiet, a classic example of a cinder cone, Sunset Crater Volcano, loomed over a dramatically altered land of lava flows and cinders.

Today Sunset Crater Volcano National Monument protects 3040 acres representing the Colorado Plateau’s most recent volcanic eruption. It is the youngest, least-eroded cinder cone in the San Francisco Volcanic Field. Much of the ground surface is covered by lava flows or deep volcanic cinder deposits; at first glance, the landscape still appears stark and inhospitable. But look again – within the dramatic geologic features are small islands of pine and aspen trees, desert shrubs, and wildflowers. These provide small but unique habitats for wildlife as well. Slowly but surely, life returns.

The significance of Sunset Crater Volcano National Monument extends beyond the geological events themselves. The powerful geologic processes that formed the volcano profoundly affected the way of life of local inhabitants during the 11th and 12th centuries and forever changed both the landscape and the ecology of the area. This volcano and its relatively undeveloped landscape provide an unparalleled opportunity to study plant succession and ecological change in an arid volcanic landscape.