Lincoln National Forest: The Sacramento Mountains and the Deepest Cave in the Americas

The Sacramento Mountains of south-central New Mexico rise from the Chihuahuan Desert floor at roughly four thousand feet to nearly ten thousand feet at the crest, creating a vertical transition from cactus and yucca to ponderosa pine and Douglas fir in the space of an afternoon's drive. Lincoln National Forest administers the high country of the Sacramento and Guadalupe Mountains, and the transition between the hot desert basin and the cool pine forest is abrupt enough to feel like entering a different region entirely.

Carlsbad Caverns National Park sits at the southern end of the Guadalupe Mountains, adjacent to Lincoln National Forest's Guadalupe Ranger District. The caverns are the surface expression of an ancient reef, the Capitan Reef, that formed in a shallow inland sea roughly two hundred fifty million years ago, then was buried, uplifted, and dissolved by acidic groundwater into a cave system of extraordinary scale. Lechuguilla Cave, discovered in its full extent in nineteen eighty-six, is one of the deepest known caves in the United States at nearly sixteen hundred feet and one of the longest in the world. It is not open to the public; its passages are accessible only to permitted scientific researchers because its formations, some growing for millions of years, cannot be restored once damaged.

The cave above it, Carlsbad Cavern itself, receives roughly four hundred thousand visitors a year, most of them descending by elevator to the Big Room, the largest single cave chamber in North America by area. At evening, between three hundred thousand and four hundred thousand Mexican free-tailed bats emerge from the cave entrance in a spiral column that takes nearly an hour to pass.