Trail to Slaughter Cave Photo by Terry Marshall

I’m flat on my belly inching through the crawl space into Spider Cave. My head lamp casts a shadowy glow into this twisting channel, but I can’t raise my head far enough to see where I’m going. The cave ceiling scrapes my back. The cave floor is rocky as a mountain stream, and jagged stones nip into my chest and thighs. I’m dragging myself - there’s not enough room to crawl - trying to follow the soles of the size ten boots ahead of me. The boots disappear around a corner.

Spider Cave? Did I say Spider Cave?

Yes, indeed, and misnamed for the tens of thousands of daddy-longlegs who coated this passage like an undulating tapestry when cavers discovered it in 1933. They’ve scurried away, those first inhabitants, to God knows where. I’ve yet to see one and this is my second trip into Spider.

The passage broadens. I crawl. No, it’s more a skittery crab walk. I pop free. I’m the sixth one into the “auditorium.” My wife and a National Park Service Ranger follow. One by one they pop into view, then scramble out to rest and breathe deeply of the sudden spaciousness. We eight fill this auditorium.

Spider is a horizontal cave - no need for ropes; there’s no rappelling. The danger here is in getting lost. We step single file as if hiking a narrow mountain trail - a trail with a rock ceiling. We negotiate ledges, clamber up and down slippery wet flow stone, often crawl. This is a wild cave - no paved trail, no electric lights. Here tourism becomes adventure. Here I’m eye-to-eye with the earth’s inner secrets.

Spider Cave challenges us up front: We descend into a stone man-hole, then slither into the heart of the hillside. In Spider Cave, we squeeze through narrow by-ways between intimate rooms - it’s chamber music compared to the grand arias of the famous Carlsbad Cavern. Spider showcases a gallery of bleached-bone-white calcite formations, extruded into misshapen, interwoven murals. It adds the intrigue of squirming belly flat through muddy passages.

This is New Mexico's Carlsbad Caverns National Park, but this intimate cave doesn’t fit the image. Most visitors remember this park from the huge Big Room - that 14-football-fields cavern - or from the oft-photographed glittering twin columns known as the Temple of the Sun.

Spider is one of five off-trail tours led by National Park Service rangers. This tour is limited to eight people, and offered only once weekly. In 1997, 540,797 visitors came to Carlsbad Caverns National Park; only 341 crawled into Spider Cave.

Lower Cave formations Photo courtesy National Park Service

Dale Pate leads an expedition of five into Lower Cave, three other rangers and me. As the park’s cave specialist, Dale’s job is to protect these caves.

We pause at the bottom of three stainless steel ladders that lead from the Big Room into Lower Cave. Dale points out the shiny, worn nodules that pit the clay trail. “This was solid clay when I first arrived,” Dale says. He’s been here seven years. Hundreds of boots have tramped this narrow trail. Nearly 2,500 people a year tour Lower Cave, up to 12 at a time, five days a week.

We follow a dirt trail flagged with two lines of orange plastic tape. The trail levels out, and becomes dry as dust. We hike on. The air becomes moist, and the trail wet. It leads to a pool. We cross by leaping from stepping stone to stepping stone. The Park Service plans to build a low bridge across this pond; too many visitors dip a heel, or toe, or full boot into the water. There’s no current; the mud doesn’t wash away.

We pause at “the Rookery,” a watery moon-scape writ small. It’s a field of tiny “craters,” each three inches in diameter, many with nests of cave pearls. The “pearls” are round, like small marbles, each built drip-by-drip around a single fleck of dirt. Many nests are empty, as if they had held cave birds that had hatched, grown, and flown away. The pearls were long ago gathered up by hoards of pre-conservation visitors and, we assume, by park staff who plucked them up and carried them away as souvenirs. Many that lie here now are replacements - found in jars and cans in other parts of the cave or on shelves in the headquarters building, and returned to their origin.

Volunteers are cleaning up the mud in this area; not today, but on weekends. They clean painstakingly with sponges, a millimeter at a time, and their patience has restored much of the Rookery floor from a muddy brown to a milky-white. Volunteers clean away mud and lint on formations throughout the cavern. They come from all over the U

.S., some from abroad. Last year, an estimated 200 cavers volunteered some 12,000 hours to restoration work, Dale says. He estimates that about a dozen of the core body of volunteers live in Carlsbad.

The Park Service has a test area here, a 4-foot by 3-foot section adjacent to the trail. It’s milky white, except for a jagged mud seepage six inches to a foot-wide along the trail-side. It’s not that visitors tromp through the test area. It’s that their footsteps slosh water, and thus mud, off the trail and onto the delicate formation.

Within the next year, the Park Service will build a 3-inch-high walkway of 3/4-inch polyethylene on stainless steel rods through here, high enough to keep boots out of the seeping water. Without it, wet boots will continue to create mud, continue to track it along the trail, continue to contribute to the muddying of the cavern floor.

Ann Marshall slithers into Spider Cave Photo by Terry Marshall

The passageway broadens as we enter the main chamber of Lower Cave. Faint paths branch out in all directions, like rabbit trails in the desert. The flagging directs visitors along a single trail. The earlier paths will never disappear; this cave cannot regenerate itself like a forest or a prairie. At best, all future wear and tear will be confined to this flagged trail.

We discover a charred flare handle on a slope beside the trail. The slope looks like the site of a miniature city that’s been leveled, and the rubble removed; what’s left is pummeled soil and slivers of cave formations, like shards of miniature sidewalks or concrete floors. The damage was done years ago, probably in the 1920s and 1930s when conservation hadn’t yet entered the caving lexicon.

This flare handle - a relic at least 60 years old - wasn’t here a month ago, Dale says. He is visibly irritated, but calm. It’s a continuing struggle to change old attitudes, he says. Not everyone is as yet attuned to his “minimum impact” philosophy - you stay on designated trails, you leave things as they are, you add nothing to the environment but a memory of your passing.

Dale brings new hires and expert cavers here to orient them to caving in the Guadalupes. Here’s what results when you’re not vigilant, he tells them. Even in Lechuguilla they find damage - not vandalized decorations, that doesn’t happen anymore - but signs that cavers have dropped their backpacks or plopped down to rest off the flagged trail. They’ve even found human feces in Lechuguilla, a cave open only to expert cavers on approved scientific or cave-mapping missions. Cave etiquette demands that you deposit it in a zip-lock bag, wrap it in foil, and carry it out.

Dale points out a bat embedded in a stalagmite. It’s completely encased by the drip-drip of water that keeps this stalagmite growing. We find others, and I study one perched atop a stalagmite. It seems poised to awake at any moment and fly sleepy-eyed off into the darkness.

A bank of popcorn-covered stalactites line the back wall. They’re more or less flat on the bottom - like trays suspended from barnacle-encrusted ropes. We’re not sure what makes them form this way, Dale says. He suspects it’s wind currents. The decorations are a potpourri of design - bulbous formations of calcite, feathery aragonite, shiny white “moon milk,” or hydromagnasite. All have the same mineral composition, but they are as different in appearance as popcorn, Irish lace, and iridescent powdered sugar.

Dale leads us to the Col. Boles formation, a pair of twin columns in the back section of Lower Cave, where Boles, the first park superintendent, led honored guests. The park’s archives attest to the trips - photographs of Boles with Amelia Earhart, Clark Gable, governors and senators and other big-wigs. Boles loved to remove a foot-long section from one of the columns to impress his visitors. We no longer do that, Dale says.

The Boles columns gleam from an internal luminescence. They have been cleaned millimeter by millimeter by volunteers. I wouldn’t have known if I hadn’t been told - they appear exactly right, exactly natural. They’re strikingly more impressive than the dull, muddy decorations nearby.

We stand quietly in the gigantic ballroom that is Lower Cave. Two finger-size silhouettes appear in the dim light of the overlook from the Big Room above. They disappear. A shard of muted voice falls over us. No one gives an order, but one-by-one we flick off our head lamps. This is a grand room, nearly barren in contrast to the past we can only imagine, like Grand Central Station stripped, but its very vastness, deep within the earth, overwhelms us. Barren? Yes, but it’s like the great Chihuahuan Desert above us - if you know where to look, and when to look, you find pockets of exquisite beauty. That’s the mystery of Lower Cave.

On our way out, cave specialist Jason Richards stops to inspect his epsomite study. He has flagged as off-limits a 3-foot section in the heart of a low-hanging passage. He points out flecks of luminescent white. Under certain conditions the flecks become a delicate white growth as fine as cotton candy, and as intricate as coral. You’d never know, not today. Without this flagging, you’d stomp through this patch of brown clay, crushing these embryos without ever noticing. He checks the humidity; it’s 95 percent. When it falls to 88, this mineral deposit will grow as if it were alive, as much as six inches a week. I’m lucky: on my first trip into Lower Cave, this very spot presented a fine eight-inch-diameter epsomite beard like a ring of fluffy hoarfrost.