This park was established to preserve Carlsbad Cavern and numerous other caves within a Permian-age fossil reef. The park contains 83 separate caves, including the nation's deepest limestone cave - 1,597 feet (486.8 m) - and third longest. Carlsbad Cavern, with one of the world's largest underground chambers and countless formations, is also highly accessible, with a variety of tours offered year round.
Carlsbad Caverns National Park is open year round. But the majority of park visitors come during the months of Jun, Jul and Aug and on weekends and holidays. The month with the least visitors is Jan. The park is open 24 hours a day, seven days a week, except Christmas Day.
The story of the creation of Carlsbad Cavern begins 250 million years ago with the creation of a 400 mile long reef in an inland sea that covered this region. This horseshoe shaped reef formed from the remains of sponges, algae and seashells and from calcite that precipitated directly from the water. Cracks developed in the reef as it grew seaward. Eventually the sea evaporated and the reef was buried under deposits of salts and gypsum.
Then, a few million years ago, uplift and erosion of the area began to uncover the buried rock reef. Rainwater, made slightly acidic from the air and soil, seeped down into the cracks in the reef, slowly dissolving the limestone and beginning the process that would form large underground chambers. At the same time, hydrogen sulfide gas was migrating upward from vast oil and gas deposits beneath the ancient reef. This gas dissolved in the percolating ground water to form sulfuric acid. The added power of this corrosive substance explains the size of the passageways. The exposed reef became part of the Guadalupe Mountains and the underground chambers became the wonder of Carlsbad Cavern.
The Cave is Decorated, Drop by Drop
The decoration of Carlsbad Cavern with stalactites, stalagmites and an incredible variety of other formations began more than 500,000 years ago after much of the cavern had been carved out. It happened slowly, drop by drop, at a time when a wetter, cooler climate prevailed. The creation of each formation depended on water that dripped or seeped down into the limestone bedrock and into the cave. As a raindrop fell to the ground and percolated downward, it absorbed carbon dioxide gas from the air and soil, and a weak acid was formed. As it continued to move downward the drop dissolved a little limestone, absorbing a bit of the basic ingredient needed to build most cave formations--the mineral calcite.
Once the drop finally emerged in the cave, the carbon dioxide escaped into the cave air. No longer able to hold the dissolved calcite, the drop deposited its tiny mineral load as a crystal of calcite. Billions and billions of drops later, thousands of cave formations had taken shape. And, oh, the shapes they took! Where water dripped slowly from the ceiling, soda straws and larger stalactites appeared. Water falling on the floor created stalagmites. Sometimes a stalactite and stalagmite joined, forming a column.
Draperies were hung where water ran down a slanted ceiling. Water flowing over the surface of a wall or floor deposited layers of calcite called flowstone. Cave pearls, lily pads and rimstone dams appeared where pools of water or streams occurred in the cave. Like oyster pearls, cave pearls were made as layer upon layer of calcite built up around a grain of sand or other tiny object. Lily pads formed on the surface of pools, while dams formed where water flowed slowly on the floor. Another type of cave formation that decorated cave walls and even other formations was popcorn, which may have formed when water evaporated and left behind calcite deposits.
Some of the more unusual formations to occur in Carlsbad Cavern are helictites, which grow seemingly without regard to gravity, their twisting shapes governed by crystal shapes, impurities and the force of water under pressure. Other rare formations are those composed not of calcite, but of aragonite, a mineral chemically identical to calcite but with a different crystal structure. These formations tend to be small, delicate and needle-like.
Carlsbad Cavern is a sanctuary for about 1 million Mexican Freetail bats. During the day they crowd together on the ceiling of Bat Cave, a passageway near the natural entrance of Carlsbad Cavern. In the darkened home they are seen only by scientific researchers. At nightfall, however, the bats leave the cave in gigantic swarms. Silhouetted against the night sky like a dark, swift-moving cloud, the bats make their most dramatic display. Other extraordinary characteristics of the bat--its natural sonar system and its ability to fly--make this creature of darkness one of great interest.
Like most species of bats, Mexican Freetails navigate and locate their prey by emitting ultra-high frequency sounds. Known as echolocation, this natural sonar system is similar to that used by dolphins and whales. When a bat's signals strike an object, they are reflected back and heard by the bat. The bat then takes whatever action is appropriate, whether it be zeroing in on a tiny moth or swerving to avoid a tree limb.
The Mexican Freetail
As many as seven types of bats may roost in Carlsbad Cavern, but none is as prevalent as the Mexican Freetail. Gray or sometimes brown, this bat is distinguished by its long, narrow wings and a free-dangling, skinney tail. Only a part-time resident of Carlsbad Cavern, this migratory bat stays here, and in other Southwest caves, from early spring through October. It flies south to tropical Mexico for the winter
In the Bat Cave
The Bat Cave serves as a warm weather home, as a daytime refuge, and perhaps most importantly, as a maternity roost, for Mexican Freetail bats. The bats migrate from Mexico to Carlsbad Cavern each year to give birth and raise their young. Under cover of darkness, away from predators or disturbances, the young are born in June. A female usually has just one offspring. Each birth occurs on the ceiling as the mother hangs by her toes and thumbs. The newborn, too, clings to the ceiling, or to its mother. For the next four to five weeks the youngster remains on the ceiling. During the day mother and young hang in clusters on the ceiling, resting, napping and nursing. As many as 300 bats may crowd into one square foot. At night, the young are left in the cave while the adults leave to feed. In July or August, each young bat takes its first flight, joining the adults on nightly feeding forays. Throughout their stay in Bat Cave the bats share their quarters with only a few insects and spiders. Finally in late October or early November, adults and young leave Bat Cave until next year for their wintering grounds in Mexico.
The Night Flight
The spectacular night flight of the Mexican Freetail begins with a few bats fluttering out of the natural entrance of Carlsbad Cavern. Then, in a matter of minutes, a thick whirlwind of bats spirals out of the cave up into the darkening night sky. the exodus can last 20 minutes or as long as 2.5 hours. Once out of the cave the undulating mass of thousands of bats flies, in serpentine fashion, towards the southeast to feed in the Pecos and Black River valleys. Once there, they begin gorging themselves on moths and other night-flying insects. Using echolocation, its sophisticated sonar system, each bat may catch and eat several stomachfuls of insects in a single night. With the coming of dawn, the bats begin flying back to the cave individually or in small groups. They reenter the cave in a fashion almost as remarkable as their departure. Each bat positions itself high above the cave entrance. It then folds its wings close to its body, and plummets like a hailstone into the blackness of Carlsbad Cavern, making a strange buzzing sound as it does. One by one, the bats return to the safety of the Bat Cave, where they sleep until reemerging in the dusk of the next day.
More than 1,000 years ago prehistoric Native Americans ventured into Carlsbad Cavern seeking shelter. They left behind no record of what their impressions of the cave were, but they did leave some mysterious drawings on cave walls near the natural entrance. Much later, in the 1800s, settlers discovered the cavern, drawn to it by the spectacle of hundreds of thousands of bats rising up out of the natural entrance in the evening. Some stayed to mine the hugh deposits of bat guano in the cave and sell it as a natural fertilizer. One such man, a cowboy named Jim White, became fascinated by the cave and spent hour after hour exploring it. White was eager to show the many natural wonders of this extraordinary place to others, but few persons believed his improbable tales of a huge underground wilderness full of unusual cave formations. It took photographs to convince skeptics that Carlsbad Caverns was everything it was said to be and more.
Black and white pictures taken by Ray V. Davis, who accompanied White on a cave trip, were displayed in the town of Carlsbad in 1915. They created a sensation. People suddenly clamored to see the marvelous cave for themselves. White took them on tours that began with an unceremonious 170 foot descent in a bucket once used to haul bat guano from the cave.
Word of the cave spread, finally reaching Washington, D.C. Again, there were nonbelievers, but in 1923 the U.S. Department of the Interior sent inspectors Robert Holley to investigate and see whether Carlsbad Cavern was truly an outstanding natural scenic wonder. Originally a skeptic, Holly wrote in his final report: "...I am wholly conscious of the feebleness of my efforts to convey in the deep conflicting emotions, the feeling of fear and awe, and the desire for an inspired understanding of the Devine Creator's work which presents to the human eye such a complex aggregate of natural wonders...."
Later that year Carlsbad Cavern was proclaimed a national monument. White, who was to continue his cave explorations for most of his lifetime, became its first chief ranger. Seven years later Carlsbad Caverns National Park was created to protect the cave. Through illustrated articles published in magazines such as National Geographic and by word of mouth, Carlsbad Cavern became one of the world's most celebrated caves. Since its establishment, the park has been expanded and today includes 46,766 acres and more than 80 other smaller caves.
And the exploration of Carlsbad Cavern continues. Experienced underground explorers, or cavers and cave scientists are the Christopher Columbuses of today, journeying beyond the boundaries of what is known into the realm of the unknown. Carlsbad Cavern attracts many men and women who are eager to shed light on some of its mysteries. Teams of cavers well versed in safe exploration techniques continue to discover new portions of the cave. Their finds in recent years include the Guadalupe Room, Carlsbad Caverns second largest room, in 1966; the exceptionally colorful and much decorated Bifrost Room, in 1982; the Chocolate High, on of the most recent discoveries, in 1993.
Scientific discoveries by speleologists, or cave scientists, are expanding our knowledge of Carlsbad Cavern in other ways. Research is answering some of the questions about the complex creation of Carlsbad Cavern, about the unfamiliar world of bats and other members of the cave community, and about the effects of man's activities on the cave.