The Colorado Plateau Underfoot

Flagstaff sits at nearly seven thousand feet on the edge of the Colorado Plateau, the enormous tableland that covers most of the Four Corners region of the American Southwest. The Plateau covers roughly one hundred thirty thousand square miles, and it is one of the least-disturbed large landscapes in the contiguous United States. Its bedrock tells a story that begins with shallow tropical seas, moves through coastal swamps, continues through vast sand deserts, and ends in volcanic upheaval, all written in the layer cake of color visible in every canyon and escarpment.

The San Francisco Peaks above Flagstaff are a volcanic remnant, the eroded remains of a stratovolcano. The cinder fields north of the city are products of Sunset Crater, which erupted roughly a thousand years ago. Meteor Crater to the east preserves the most visible impact scar on earth. Walnut Canyon to the east and the Grand Canyon to the northwest expose cross-sections of the plateau's sedimentary record going back hundreds of millions of years.

The forest that covers the plateau around Flagstaff, the largest contiguous ponderosa pine forest in North America, is a product of altitude. At sea level this latitude would support Sonoran desert. The mile-high elevation intercepts enough moisture to sustain a forest that, in a good year, smells of vanilla in the heat of the afternoon, a compound in the bark that releases when the temperature climbs. That is the landscape that anchors everything else here: the observatories, the ancient villages, the sacred mountains, the astronauts training for the Moon.