Photo: Stalactites hanging from caverns

Stalactites hang like daggers in the Big Room at Carlsbad Caverns National Park in New Mexico. The huge space covers more than eight acres.

Photograph by Tim Starr, submitted to My Shot

Location: New Mexico

Established: May 14, 1930

Size: 46,766 acres

The Chihuahuan Desert, studded with spiky plants and lizards, offers little hint that what Will Rogers called the "Grand Canyon with a roof on it" waits underground. Yet, at this desert's northern reaches, underneath the Guadalupe Mountains, lies one of the deepest, largest, and most ornate caverns ever found.

Water molded this underworld four to six million years ago. Some 250 million years ago, the region lay underneath the inland arm of an ancient sea. Near the shore grew a limestone reef. By the time the sea withdrew, the reef stood hundreds of feet high, later to be buried under thousands of feet of soil. Some 15 to 20 million years ago, the ground uplifted. Naturally occurring sulfuric acid seeped into cracks in the limestone, gradually enlarging them to form a honeycomb of chambers. Millions of years passed before the cave decoration began. Then, drop by drop, limestone-laden moisture built an extraordinary variety of glistening formations—some six stories tall; others tiny and delicate.

Cave scientists have explored more than 30 miles (48 kilometers) of passageways of the main cavern of Carlsbad, and investigation continues. Visitors may tour three of these miles (five kilometers) on a paved trail. Slaughter Canyon Cave provides the hardy an opportunity to play caver, albeit with a guide. The park has more than a hundred other caves open primarily to specialists.

Some visitors think the park's most spectacular sight is the one seen at the cave's mouth. More than a quarter million Brazilian (Mexican) free-tailed bats summer in a section of the cave, and around sunset they spiral up from the entrance to hunt for insects. The nightly exodus led to the discovery of the cave in modern times. Around the turn of the 20th century, miners began to excavate bat guano—a potent fertilizer—for shipment to the citrus groves of southern California. One of the guano miners, James Larkin White, became the first to explore and publicize the caverns beyond Bat Cave.

How to Get There

The park is off US 62/180, 20 miles southwest of Carlsbad and 164 miles east of El Paso, Texas. For the visitor center, turn west at Whites City and drive seven miles. For Slaughter Canyon, turn west on County Road 418, five miles south of Whites City; drive another 11 miles, some unpaved, to the parking lot. Airports: Carlsbad, New Mexico, and El Paso, Texas.

When to Go

Year-round. The weather underground remains a constant 56°F. The main cavern gets crowded, especially in summer and on major holiday weekends. Either spring or fall, when the desert's in bloom, is an excellent time to go. You'll see the bats fly from April or mid-May through October.

How to Visit

One full day allows you time to tour the main cavern and take a nature walk or a drive before watching the bats fly at sunset. For a second day's activity, reserve space on a tour of "unimproved" Slaughter Canyon Cave, if you're ready for a more rugged caving experience.

At the visitor center, select either the Natural Entrance Tour or the Big Room Tour (both are 1.25-mile walks). Try the first unless you have walking, breathing, or heart problems. It starts at the natural entrance and is mostly downhill, except for one stretch where you climb 83 feet; an elevator whisks you back to ground level. The Natural Entrance Tour is more intimate and may be less crowded than the Big Room.

The Big Room Tour begins with an elevator ride directly to the Big Room, in which you can see most of the types of formations visible in areas of the cave not open to the public. If after this tour you want to see more caves, take the elevator back up to ground level and proceed with the first half of the Natural Entrance Tour.

Another option, the Kings Palace Tour visits the stunning formations in the scenic rooms.

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