The Caverns Of Carlsbad Beneath The Surface Of New Mexico’s Chihuahuan Desert Lie 300 Or So Limestone Caves

We were mindful of the heat, cautious about scorpions and careful to carry plenty of water. But a thorn by any other name is, after all, still only a thorn. So I circled the cactus a walking stick cholla and stood on tiptoe to peer into a softball-sized bird’s nest cradled in its knobby green arms.

I leaned forward only slightly, stopping inches (or so I thought) from invading the plant’s personal space. And then, zap - quick as buckshot, I was pierced. Several score of all-but-invisible, rapier-thin tines, barbed to better make their point, pinned my shirt to my chest. Welcome to the desert, tenderfoot.

We had come to New Mexico’s Chihuahuan Desert in mid-May in hopes of finding the cactuses in bloom and were not disappointed. A dry spring had delayed April’s blossoms, which now lit the desert floor like coals shot from a campfire.

Brilliant yellow prickly pear blossoms, magenta hedgehog cactuses and scarlet and green wands of ocotillo dancing with northbound hummingbirds bloomed in concert.

We had also come, of course, to see the vast, surreal Carlsbad Caverns, limestone caves that were named a national monument in 1923 and a World Heritage Site last year.

Just a few minutes inside the hollow core of that melting world is long enough to understand why no one believed the cavern’s early explorers when they struggled to describe what they’d seen below ground.

The movies filmed in these caves (“King Solomon’s Mines,” “The Gargoyles,” “Voyage to the Center of the Earth”) suggest the effect the caverns have on the human psyche.

The caves of Carlsbad Caverns National Park underlie the Chihuahuan Desert, the highest and wettest of North America’s four deserts. (The Sonora, Mojave and Great Basin are the others). A 400-mile-long limestone ridge, an offshore reef in 250 million BC, lies between the ancient seabed and land that came up for air to form the Guadalupe Mountains 20 million to 40 million years ago.

Fresh water running off the mountains mingled with briny water and hydrogen sulfide gas rising from oil and gas deposits to form weak carbonic and sulfuric acids. Over millions of years the acidic water ate huge holes in the reef, which in cross section must look like a sponge.

There are 300 or so known caves in the Guadalupe Ridge; 87 of them within the national park. Of those, 10 are open to the public, although access to most requires visitors to prove their competence as spelunkers capable of using climbing gear.

The most spectacular cavern, however, is the easiest to see, and more than a half-million humans and 1 million Mexican free-tail bats visit it each year. Tourists gather nightly to watch the bats exit the cave like a plume of smoke.

Elevators that are just steps from the parking lot descend 754 feet in only one minute to whisk cavers down to a netherworld of stone giants, yawning pits, crystal pools and needled ceilings.

We opted to make the winding mile-long descent down a paved walkway that begins at the natural entrance. This hike, with time for gawking and photographs, takes about an hour. Carry at least one spare camera battery. Frequent flashes exhausted ours before we reached the bottom. A sweater or light jacket would also have made the cave’s 56-degree temperature more comfortable.

The caverns quickly become amphitheaters, and we walked openmouthed and antlike through the enormous chambers. Bizarre formations - stalactites and stalagmites, soda straws, cave clouds, columns washed in flowstone, rock curled like ribbon candy, pillars coated in stone popcorn and stalactites shaped like lions’ tails - lined our path through the largest natural limestone chamber in the world. The Big Room alone is 1.2 miles in circumference and hundreds of feet high.

Dim and artful illumination, the work of a Hollywood set designer, gently highlights speleothems yet preserves much of the mystery of The Temple of the Sun, Boneyard, Hall of Giants and other famed grottoes.

The same can’t be said, however, of the cavern’s subterranean snack bar and souvenir shop, a tacky theme-park touch about as appropriate as a hot-dog stand in the Lincoln Memorial.

The main cavern and all it offers is worth a day, but we cut short our first tour to see a cavern in a more natural state. Only two groups of 25 people per day are allowed into Slaughter Canyon Cave, which is open to the public on weekends from mid-August through May and daily in the high tourist season.

Tours of the cave, which was named for rancher Charles Slaughter, are booked weeks or months in advance. We were very lucky to secure places on the 1 p.m. tour, a ranger said.

The cave, 23 miles across rangeland from the visitors center, was discovered in 1937 by a goatherd whose flock used it to take shelter from a storm. Slaughter Cave is not pristine. It was mined for bat guano from shortly after its discovery until 1957 and remains much as the miners left it.

The cave’s entrance is 500 feet above the valley, reached by a halfmile, 45-minute hike roughly equivalent to ascending the stairs of a 50-story building. The park guidebook describes this tour as a strenuous one requiring sturdy shoes, good health, a flashlight and water.

We set out just past noon. In 15 minutes we were wheezing. In 20, despite frequent slugs from water bottles, we had the headaches that signal the onset of dehydration. A long water break restored fluids claimed by the thin, bone-dry air, but we were mystified. We were both in good shape. Yet a measly half-mile hike had left us bushed.

At the cave’s mouth we learned why we’d had no trouble making reservations and why we were tired. An entire busload of tourists had canceled because of the heat. The air temperature, Ranger Julie Hecht said, was 105 degrees and the rocks much hotter.

Primitive humans visited but did not live in most of Carlsbad’s caves. They rarely ventured past the “twilight zone” where natural light fades then fails. “Since you’ll be getting a private tour, we’ll get to hit all the hot spots,” Hecht said to my brother and me as we descended through the dusk and into absolute darkness.

For nearly two hours, the three of us walked and scrambled through the enormous cave. In the guano trenches, tiny bat bones protruded like twigs from the walls. Bats that fell to the cave floor were usually devoured quickly by hordes of carnivorous beetles living in the accumulated dung. The beetles had vanished with the bats, but pale cannibalistic cave crickets roamed the floor in search of smaller brethren.

The oldest of the reddish-brown bat droppings have been carbon dated at 32,000 years, Hecht said. The species of bat that deposited it is now extinct. Most of the guano from this cave, like the 100,000 tons mined from the main cavern, was hauled to California and used to fertilize citrus groves.

Slaughter Cave’s miners used the colossal, fluted column called “The Pillar of Hercules” as a guidepost. We circled around it to the room with the cave’s most famous formation, “The Christmas Tree.”

As we walked, Hechtman explained how speleologists thought shields - inches-high rimstone dams that wind across the cave floor like a scale model of the Great Wall of China and other cave decorations - are thought to have been formed.

“We really know next to nothing about caves. For a long time we were looking for the lost river of the Carlsbad as an answer to their formation,” Hecht said. “It was not until 1970 that a woman named Carol Hill came up with the sulfuric acid explanation.”

We sat on huge fallen stalactites and marveled at the great Christmas Tree frosted with calcite crystals that sparkled in the light from a single match.

We sat in darkness black as the inside of a cow while Hecht told ghost stories and tales of lost cavers.

Then she challenged us to find our own way out. Though much of the rocky path was lined with white tape, I soon took a turn leading deeper into the cave.

Without lights, it would be nearly impossible to find the entrance without injury. In the cave’s pitch black, a poor choice could mean a long drop to rocks as rough as a wood rasp.

A week could be spent exploring Carlsbad Caverns and nearby Guadalupe Mountain National Park. There are hikes into shady canyons, swimming in the Pecos River, scenic drives, horseback rides and museums to visit.

We, however, had little time, and had left the main cavern’s major attractions unseen. The closest lodgings other than campgrounds are in White’s City, a tourist complex owned by one family where prices appeared to reflect the convenient location. We opted to drive the 27 miles to Carlsbad, a friendly town whose major industries are tourism and potash mining.

It takes great faith to order fish in the desert, but Beaver’s Restaurant on South Canal Street made believers of us with platters of sweet catfish fried in a lightly spiced cajun batter.

Fueled again, we returned to the park to marvel at the change of shifts when the cave swallows drop into the cavern and the bats emerge by the hundreds of thousands.

We had already made the long descent into the cavern on foot - a great way to build suspense but not for the faint of foot. This time, we took the elevator down and toured the most famous portions of the cavern with our 50-cent rental radios squawking out explanations. It was as if, like Alice, we had shrunken enough to roam the interior of a geode whose crystal spears formed the walls and the ceiling hundreds of feet overhead.

Hours later, we rose up from the halls of mountain kings and drove through hills the color of deer hide. It was hot and the sun was harsh.

We stopped to sit under limestone overhangs that sheltered Apache families in long-ago summers. The world beneath us seemed hollow and full of mystery, as if, with one stamp of our feet in the wrong spot, we would disappear.

MEMO: This sidebar appeared with the story: IF YOU GO Information can be obtained by writing Carlsbad Caverns National Park at 3225, National Parks Highway, NM 88220-5534 or by calling the park visitors center at 505-785-2232 or via modem at http://www.caverns.com/ccgma. Park fees are modest. A daily pass is $5 for adults, $3 for children 6-15, and free for those under age 6. Senior citizens are admitted for half price. There are additional fees for some tours. The tour of Slaughter Canyon Cave, for example, costs $8 for adults and $4 for children and senior citizens. Reservations for tours should be made well in advance particularly in summer. Much of the park, including some nature trails and the most spectacular of the main cavern’s rooms are accessible to the handicapped. The urge to photograph the cavern’s fairytale landscape is irresistible but good results require more know-how than taking snapshots. Video cameras are prohibited, as is taking photographs during guided tours. No lodging is available within the park itself, but campgrounds and motels abound nearby in White’s City and in Carlsbad, 27 miles northeast.