New Mexico
An out-and-back trail visible from above follows the ridge of the Dragon’s Back, running from the tail up to the head.
Northwest New Mexico is one of the driest places in the United States—the region gets less than twelve inches of rain a year, most of it during the late-summer monsoon season. But despite the aridity, this desert is shaped by water. During the Mesozoic Era, starting around 160 million years ago, what is now New Mexico was flooded by a shallow inland sea that covered most of the southwestern United States. The sea was very salty and rich in minerals that left behind extensive deposits of limestone and gypsum.
From an aerial perspective, the Dragon’s Back lives up to its name, with its head to the east (left) and tail curving to the west (right).
These layers of gypsum, a white crumbly rock, have eroded away to sculpt the Dragon’s Back: a striking ridgeline with a bulbous head and a tapering tail that, from the air, has the appearance of a great white serpent. Stretching two and a half miles, it stands out starkly against the contrasting red and orange landscape. Look closely and you may see tiny mountain bike riders or hikers making their way along the spine of the Dragon’s Back. The top of the Dragon’s Back is wide enough to bike or hike across without much danger of falling off, but narrow enough in some sections to trigger vertigo. The trail is not for the faint of heart—gypsum is a water-soluble mineral and eons of rare rains have melted a few sinkholes into the top of the ridge, some big enough to swallow a bike and its rider whole.
On the trail near the dragon’s head, one can look across the anticline back at the tail (to the left).
The east side of the ridge drops steeply down into an enormous bowl, carved out by erosion over the past 150 million years. This bowl is actually an anticline: a fold in Earth’s crust that creates a convex dome. The anticline here, however, is no longer a dome—the middle layers have been scooped out by erosion, leaving behind a bowl with upswept sides. The feature is so unique that geology classes from the University of New Mexico in Albuquerque journey here each year on field trips to see it in person.
The name Dragon’s Back is fitting, and not just for the formation’s distinctly reptilian shape. During the Mesozoic Era, when the layers that form the Dragon’s Back were deposited, dinosaurs dominated the land and sea. New Mexico is home to some of the most productive dinosaur boneyards in the country, including the Ojito Wilderness, just ten miles south of the Dragon’s Back, where remains of one of the longest dinosaurs found to date—the 110-foot-long Seismosaurus—were uncovered in 1985. Other fossils are common in the area, including whole petrified trees.
A few deep sinkholes have opened along the Dragon’s Back ridge trail, which is made up of water-soluble gypsum.
Flying into or out of Albuquerque, New Mexico, you may catch a glimpse of the Dragon’s Back. From the air, the formation appears as a curving white ridge against a red background, just west of U.S. Route 550.
