Sunset Crater | U.S. Geological Survey
Sunset Crater. Sunset Crater, located about 25 km (15 mi) northeast of Flagstaff, Arizona, is one of the youngest scoria cones in the contiguous United States and is the youngest of about 600 such cones in the San Francisco Volcanic Field. Sunset Crater, a basaltic cinder cone in the San Francisco Volcanic Field, Arizona, erupted in 1085 A.D.