Red Mountain is a volcanic cinder cone in northern Arizona’s Coconino National Forest, about 25 miles northwest of Flagstaff. Part of the San Francisco volcanic field, it rises about 1,000 feet above the surrounding land and stands out for its red color and unusual U-shaped form opening west. Scientists suggest it formed nearly 740,000 years ago, likely from a vent now buried beneath the cone’s intact arms. Its asymmetrical shape and large inner amphitheater remain subjects of debate, with possible causes including strong winds, lava flows, or a steam explosion. The mountain is also noted for mineral grains often mistaken for Apache tears.