One of the largest and most spectacular cave systems in the world, Carlsbad Caverns National Park comprises more than 100 known caves that snake through the porous limestone reef of the Guadalupe Mountains. Fantastic and grotesque formations fascinate visitors, who find every shape imaginable (and unimaginable) naturally sculpted in the underground -- from frozen waterfalls to strands of pearls, soda straws to miniature castles, draperies to ice-cream cones.
Formation of the caverns began some 250 million years ago, when a huge inland sea covered this region. A reef formed, and then the sea disappeared, leaving the reef covered with deposits of salts and gypsum. Eventually, uplifting and erosion brought the reef back to the surface, and then the actual cave creation began. Rainwater seeped through cracks in the earth's surface, dissolving the limestone and leaving hollows behind. With the help of sulfuric acid, created by gases released from oil and gas deposits farther below ground, the cavern passageways grew, sometimes becoming huge rooms.
Once the caves were hollowed out, nature's artistry took over, decorating the rooms with a variety of fanciful formations. Water dripped down through the rock into the caves, dissolving more limestone and absorbing the mineral calcite and other materials on its journey. Each drop of water then deposited a tiny load of calcite, gradually creating the cave formations that lure visitors to Carlsbad Caverns each year.
Although American Indians had known of Carlsbad Cavern for centuries, settlers didn't discover it until sunset flights of bats emerging from the cave attracted ranchers in the 1880s. The first reported trip into the cave was in 1883, when a man supposedly lowered his 12-year-old son into the cave entrance. A cowboy named Jim White, who worked for mining companies that collected bat droppings for use as fertilizer, began to explore the main cave in the early 1900s. Fascinated by the formations, White shared his discovery with others, and word of the magical underground world soon spread.
Carlsbad Cave National Monument was created in October 1923. In 1926, the first electric lights were installed, and in 1930 Carlsbad Caverns gained national park status.
Underground development has been confined to the famous Big Room, one of the largest and most easily accessible of the caverns, with a ceiling 25 stories high and a floor large enough to hold more than six football fields. Visitors can tour parts of it on their own, aided by an excellent portable audio guide, and explore other sections and several other caves on guided tours. The cave is also a summer home to about 400,000 Brazilian (also called Mexican) free-tailed bats, which hang from the ceiling of Bat Cave during the day. They put on a spectacular show each evening as they leave the cave in search of food, and again in the morning when they return.
In addition to the fascinating underground world, the national park has a scenic drive, an interpretive nature trail, and backcountry hiking trails through the Chihuahuan Desert.