Sunset Crater is a cinder cone located north of Flagstaff, Arizona in the United States. The crater lies within the Sunset Crater Volcano National Monument.
Sunset Crater is the youngest in a string of volcanoes (the San Francisco volcanic field) that is related to the nearby San Francisco Peaks. It first erupted in 1064, and the last major eruption occurred in 1180, raising the volcano’s height to about 300 meters. A final burst of activity in the 13th century painted the upper portion of the otherwise black cone with bright red and orange rocks, giving the volcano its name. The volcano has partially revegetated, with pines and wildflowers. The crater has given its name to the Sunset Crater Beardtongue (Penstemon clutei).
Damage from hikers forced the National Park Service to close a trail leading to the crater, but a short trail at the base remains.
The hiking trail below the summit skirts the substantial Bonita Lava Flow. This hardened lava is black and appears fresh as it has devastated the forest in its path. The lava flow also created an ice cave or tube that is now closed to the public after a partial collapse.