| Humphreys Peak (12,633 feet) has the highest elevation in the San Francisco Volcanic Field. Humphreys Peak is the second mountain summit from the right side of this image. All the peaks shown are part of San Francisco Mountain, a great dormant volcano. At its maximum height, the ancient volcano may have approached 15,000 to 16,000 feet in elevation. The volcano then experienced a collapse, either by gravity induced landslide or a lateral blast eruption similar to the 1980 eruption of Mount St. Helens. This event created the great bowl-shaped amphitheater in the upland area east of Humphreys Peak (Fellows, 2000, 2003). During the ice ages of the Pleistocene Epoch, small glaciers carved the upper mountainsides of Humphreys Peak and surrounding summit area. San Francisco Mountain and the surrounding forested landscape are part of the Coconino National Forest. |
