Sunset Crater Volcano National Monument

Between A.D. 1064 and 1180, 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 fire bombs 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, and it may be one of the longest-lived cinder cone volcanoes, with an eruptive cycle that may span more than 100 years. At Sunset Crater Volcano you will see a cinder cone rising 1,000 feet above the surrounding landscape. 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.

To protect this fragile resource, Sunset Crater Volcano is closed to climbing and hiking. However, other cinder cones in the area may be climbed and offer short but rugged hiking trails. Squeeze-ups and hornitos are just two of the fascinating volcanic features you'll encounter while exploring the park.

 

 

 

 

Location:

12 miles north of Flagstaff off Hwy 89

 

Park Features:

Hiking Trails
Scenic Drive

Facilities:

Visitor Center

Season:

Open year round

Hours:

9:00 am - 5:00 pm

Admission Fee:

$3 per person

Address:

Route 3 Box 149
Flagstaff ,   86002

Phone:

928-526-0502

Fax:

928-526-4259

 

 


To get there from Flagstaff, take Hwy 89 north for 12 miles (19 km), turn right on the Sunset Crater - Wupatki Loop road and continue 2 miles (3 km) to the visitor center.

 

 

Sunset Crater, Arizona

Location: 35.4N, 111.5W
Elevation: 8,026 feet (2,447 m)


Sunset Crater. Photograph courtesy of the National Park Service.

Sunset Crater is in the eastern part of the San Francisco volcanic field. Sunset Crater, one of the youngest scoria cones in the contiguous United States, began erupting between the growing seasons of 1064 and 1065 A.D. Eruptions continued in the area for many decades. The cone was named by John Wesley Powell, first director of the U.S. Geological Survey, for the topmost cap of oxidized, red spatter which makes it appear bathed in the light of the sunset. The red, pink, and yellow colors at the top of the cone are silica, gypsum, and iron oxide that formed from fumaroles.


Aerial view looking west to Sunset Crater. Photography by Wendell Duffield, U.S. Geological Survey.


Sunset Crater. Photograph courtesy of the National Park Service.

Sunset Crater is a nearly symmetrical cone made of dark-gray scoria and scattered bombs. The cone is about 1,000 feet (300 m) high and 1 mile (1.6 km) in base diameter.


The main crater at the summit is 400 feet (120 m) in diameter. Photograph courtesy of the National Park Service.

The eruption at Sunset Crater covered and area of 800 square miles (2,100 square kilometers) with lapilli and ash. The eruption was Strombolian in style and large, with eruption columns as high as several hundred feet (meters). The tephra covers parts on the Bonito and Kana-a lava flows which were erupted from Sunset Crater. The Bonito lava flow erupted from the west and northwest base of the cone and covered an area of 1.8 square miles (4.6 square kilometers). The Kana-a lava flow was erupted from the base of the east side of the cone and traveled 6 miles (9.6 km) down a wash.


Aerial view of Sunset Crater. Photography courtesy of National Park Service.

The Sunset eruption is unusual because the volume of volcanic products (about 0.7 cubic miles, 3 cubic km) is large for a strombolian event, the air fall dispersal was large, and the discharge rate for magma was high.

The Sunset event had a severe effect on the Sinagua Indians that lived in the area, forcing them to temporarily leave.


Inside the main crater of Sunset Crater. Photography courtesy of National Park Service.

In the 1920s, H.S. Colton saved the cone from severe damage by averting the attempt of a Hollywood movie company to blow it up in order to simulate an eruption. This led to the establishment of the Sunset Crater National Monument.