Carlsbad Caverns National Park, ? Rangers sit visitors on stone benches at the huge mouth of Carlsbad Caverns National Park and warn them: Don’t touch the formations. Stay on the trails. No gum or food in the cave. No running. No shouting.

Then tourists begin trekking into the famed limestone caverns on a rock-lined switchback trail, dropping from the brightness and heat of the Chihuahuan desert into a dim cave that remains a constant 56 degrees.

Carlsbad Caverns National Park is New Mexico's most popular tourist attraction. After a few years of declining visits, people are again flocking to the natural wonder.

The drop of some 750 feet in about a mile bottoms out at the 14-acre Big Room, marked by formations bearing picturesque names such as Rock of Ages or Painted Grotto; a ceiling that soars 200 feet into the darkness overhead; and vertigo-causing glimpses into even deeper parts of the 4 million-year-old cave.

New Mexico’s favorite tourist attraction, after a few years of declining visitors, is booming again.

The number of visitors in the first three months of 2002 increased 15.6 percent over the same period last year. In February, the park temporarily ran out of brochures in English, although they still had Spanish-language editions. Many motels surrounding the park filled up over Memorial Day weekend, the holiday that heralds Carlsbad Cavern’s expanded summer hours.

The U.S. Postal Service just unveiled a 23-cent postcard with an image of the caverns’ Giant Dome, the tallest formation in the Big Room. The column 62 feet tall and 100 feet around at its base is in the Big Room’s Hall of Giants.

Easier all the time

Carlsbad carved out of limestone by the slow drip of acidic water became a national monument in 1923 and a national park seven years later.

Early visitors faced a strenuous, all-day trip over dirt trails and steep wooden stairways that climbed and descended the equivalent of an 83-story building in about five miles.

The wooden staircase built in 1925 at the caverns’ natural entrance eliminated the need for visitors to be hoisted into the cave in large buckets once used to mine bat guano.

Today, people can walk in the natural entrance some 1 1/4 miles to the Big Room or descend in a high-speed elevator for the 1 1/4-mile Big Room tour, the highlight of the main cave.

“We tell people right up front, it’s long and steep and you need to be in moderately good physical condition” for the natural entrance, park spokeswoman Bridget Eisfeldt says. “If you have bad knees or anything like that, it’s a pretty good walk.”

The asphalt trails have metal handrails, and everyone rides elevators 750 feet to the surface, avoiding an exhausting uphill hike. The first two elevators were built in 1931; two more were added in 1955. All four were replaced in the 1970s and renovated in 1998.

Near the elevator shaft is a vast underground lunchroom that serves boxed lunches, snacks, water and soft drinks. It took an act of Congress in 1994 to keep the lunchroom open after the National Park Service, backed by some caving groups, proposed closing it.

	Carlsbad Caverns National Park features a 750-foot deep limestone cave full of formations ranging from hundreds of feet tall to dainty ones called soda straws. The main cave has a system of paved trails, most wheelchair-accessible, and lighting on the more spectacular formations.Getting there: From the city of Carlsbad, take U.S. 62 southwest to N.M. 7, a trip of about 27 miles through Chihuahuan desert country.Admission: $6 adults (age 16 and up); $3 children 6-15; under 3 free. National parks passes accepted. Visitors also can rent state-of-the-art audio guides for $3.Tours of caves outside the main Carlsbad Caverns cost extra and require reservations up to six weeks in advance. Prices range from $7 to $10 for adults and $3.50 to $10 for children. For reservations call (800) 967-CAVE (2283).Evening bat flights: Programs are held each evening, barring rain, at the natural entrance amphitheater through October or until the bats migrate to Mexico for the winter. The programs are free and begin at dusk.Other activities: A one-mile paved trail begins near the visitors center and highlights desert plants. A 9.5-mile, one-hour drive on a gravel road through the Chihuahuan desert is suitable for most vehicles. The park’s wilderness areas offer day hikes and backcountry camping, which requires permits. The visitors center includes exhibits, gift shops and a restaurant.Hours: Carlsbad Caverns’ visitors center is open daily except Christmas. Summer hours, which last from Memorial Day weekend through Aug. 18, are from 8 a.m. to 7 p.m. Self-guided Big Room tours run from 8:30 a.m. to 5 p.m. The self-guided natural entrance route is open from 8:30 a.m. to 3:30 p.m.Information: Call (505) 785-2232 or visit the park’s Web site at www.nps.gov/cave.

Eisfeldt acknowledges reactions to the lunchroom vary.

“Some people like it. They think it’s nostalgic, historic, part of the cave,” she says. “Others are shocked to find a lunchroom down there.

“When you first start the tour, you’re told you can’t have any food in the cave. … Then you go down and there’s this lunchroom.”

Ranger-guided group tours of the park’s first decades gave way to self-guided tours for the Big Room in 1967 and for the natural entrance in 1972. Ever-increasing visitors made self-guided tours necessary; ever-improving technology made them possible, Eisfeldt says.

The first system used low-power transmitters in the trails to transmit audio messages at designated spots. A self-contained CD-ROM version was introduced in 1997. The third-generation guide introduced in April is designed to be more user-friendly.

Limited tours

The main cave that gives the park its name stretches for more than 30 miles, most of it not open to the public. There also are 100 other caves within the park’s boundaries, most of them also inaccessible.

However, some separate caves or parts of Carlsbad Caverns not on the regular route are open for reservation-only, guided tours. Depending on the cave, tours cost from $7 to $20 for adults in addition to the $6 national park admission fee.

The slow Drip of acidic water carved the caverns out of limestone and created fantastic stalactite and stalagmite formations.

Some tours require basic caving knowledge, or at least no fear of tight places, Eisfeldt says.

Spider Cave tour, limited to seven people, explores that separate cave and requires handling tight squeezes and crawling, she says.

The Hall of the White Giant tour, limited to eight, sometimes sells out months in advance, Eisfeldt says. “You get to crawl around and get dirty.”

Tours of Spider Cave and Hall of the White Giant are offered only on Saturdays and Sundays.

A tour of the separate Slaughter Canyon Cave is a flashlight trip. A tour of Lower Cave has no crawling, but visitors have to negotiate ladders and dirt trails.

For those who aren’t quite so adventurous, rangers offer the Left Hand Tunnel and the Kings Palace tours within the main cave. Left Hand Tunnel is a lantern tour; Kings Palace is on a paved trail that was part of the regular tour until 1995, when it became guided because of vandalism.

“It’s a highly decorated area,” Eisfeldt says. “We wanted to make sure we didn’t start losing stalactites.”

Bat programs

From Memorial Day into October, rangers also give evening bat flight programs. Visitors sit at the natural entrance amphitheater for the dusk flight of 300,000 bats, mostly Mexican freetails, on their forays for food. Eisfeldt says the best times are the end of July and early August when young bats first venture out with their parents.

The bats live in a section of the cave closed to visitors about a half-mile from the entrance.

The second Thursday in August Aug. 8 this year brings the annual Bat Flight breakfast, when visitors gather before dawn to watch the other end of the flight bats returning to the cave.