Sunset Crater Volcano "The contrast in the colors is so great
that on viewing the mountain from a distance the red cinders
seem to be on fire. From this circumstance the cone has been
named Sunset Peak." Sunset Crater: A Colorful Volcanic Cone The
cones and lava flows of the San Francisco volcanic field, which
covers about 2,000 square miles of the southwestern Colorado
Plateau, result from several million years of volcanic activity.
These powerful underground forces changed the landscape
dramatically beginning in the winter of AD 1064-65. Sunset
Crater appeared when molten rock sprayed out of a crack in the
ground high into the air, solidified, then fell to earth as
large bombs or smaller cinders. As periodic eruptions continued
over the next 200 years, the heavier debris accumulated around
the vent creating a 1,000-foot cone. The lightest, smallest
particles blew the farthest, dusting 800 square miles of
northern Arizona with ash. Perhaps as spectacular as the
original pyrotechnics were two subsequent lava