Carlsbad Caverns National Park

Hidden beneath the surface of the Chihuahuan Desert in New Mexico’s Guadalupe Mountains is one of the natural wonders of the world. Carlsbad Caverns National Park is one of the most extensive cave systems in the world with 120 known caves and new ones being discovered with further exploration. The park’s namesake, Carlsbad Cavern, is over 30 miles long with miles of paved, lite pathways for visitors to explore this underground lair. Elevators take visitors down 750 feet below the surface to the Big Room which is large enough to hold two US Capitol buildings. One of the newer discoveries, Lechuguilla Cave (1986), is more than 140 miles long making it one of the longest caves in the world. It is also the deepest cave in North America at 1,604 feet deep.

The origin of Carlsbad Cavern begins between 250-300 million years ago during the Permian Period. Long before the age of the dinosaurs, a shallow inland sea covered an area known as the Delaware Basin in what is today’s southeast New Mexico and west Texas. A 400-mile-long, horseshoe-shaped reef formed along the edge of this inland sea composed mostly of sponges and algae. As each generation grew atop its ancestors, pressure compressed the underlying reef into limestone. Several million years later, Earth’s uplifting crust cut off this inland sea from the rest of the vast ocean to the west. As the Delaware Basin rose, cracks developed in the reef rock allowing rainwater and seawater to seep down and start dissolving the reef rock creating Swiss-cheese like interconnected voids called spongeworks. Over time as the sea evaporated, the basin filled with salts, gypsum, and calcite burying the reef.

Around 15-20 million years ago, movement of the tectonic plates began creating the alternating valleys and mountains of the Guadalupe Range that Carlsbad Caverns National Park lies in. The rise of the mountains exposed the buried reef rock and as the water table drained, the cavities within the spongeworks filled with air and rising hydrogen sulfide gas. This gas led to the creation of sulfuric acid which dissolved the limestone and began the process of creating the huge chambers that Carlsbad Caverns is famous. As the uplift of the Guadalupe Range occurred, the water table stayed at the same level and that is why we see caves in layers. Within Carlsbad Caverns, Bat Cave is older (6 million years) then Lower Cave (4 million years).

Carlsbad Cavern’s decoration of stalactites (hang from ceiling), stalagmites (rise from floor), and an incredible variety of other formations began slowly forming over 500,000 years ago, well after the caves had formed. The formation of decorations depends on water dripping down through the limestone so it occurred during a time when the climate was wetter and cooler. As the water trickles down, it picks up carbon dioxide gas from the air and soil forming a weak acid. The acidic water dissolves a little limestone and also picks up the mineral calcite with is essential to all cave formations. Each drop of calcite-laden water deposits its minerals as the water evaporates. After hundreds of thousands of years and billions upon billions of drops later, the formations of Carlsbad Caverns took shape to what we see today.

Over 1,000 years ago Native Americans ventured into Carlsbad Cavern and left mysterious drawings on the cave walls near the natural entrance. In 1898, at the age of 16, local resident Jim White noticed a black cloud billowing out of the ground at dusk. When he went to investigate, he discovered hundreds of thousands of bats emerging from a large hole in the ground. He returned several days later with rope and lanterns. Over the next 45 years, Jim White would spend his life exploring the cave and supporting its use for tourism. In 1915 photographs taken by Ray V. Davis, who accompanied White on a cave exploration, were displayed in the town of Carlsbad, New Mexico. The photos created a sensation and people began flocking to the Carlsbad Cavern where White would take them on a cave tour which began with a 170-foot descent in a bucket once used to harvest bat guano from the cave. Word of the cave spread to Washington, DC where it was declared a national monument in 1923 and then proclaimed Carlsbad Caverns National Park in 1930. It has become one of the world’s most celebrated cave systems and was designated as a World Heritage Site in 1995.

Visitors to Carlsbad Caverns National Park have two options for visiting the caves. If you feel like hiking, which I did, you can enter through the natural entrance which is a short quarter-mile hike from the visitor center. Hikers descend down into the large hole in the ground and enter the large Bat Cave (200 feet below surface). There is still some daylight which floods the Bat Cave, but as you make your way down the Main Corridor into the Devil’s Den (500 feet below surface) visitor enter the dark zone. The Natural Entrance Route that I took is a dimly lit, paved footpath with hand rails and numerous stations with information panels and rest areas. Although there aren’t many cave decorations along the 1.25-mile Natural Entrance Route, the enormous size of the caverns is just remarkable.

Eventually, the Natural Entrance Route dumps you into the Big Room (750 feet below the surface) where you meet other visitors who have elected to take the elevator down from the visitor center. There is a gift shop, snack bar, and restrooms here as well. The Big Room Route is another 1.25-mile path around the perimeter of this highly decorated 8.2-acre chamber. There are thousands of formations, in this Carlsbad Caverns’ largest chamber, with such names as Bottomless Pit, Giant Dome, Rock of Ages, and Top of the Cross. The immense size and decorations of the Big Room are just overwhelming, and a must see for all visitors to Carlsbad Caverns National Park. When you are done enjoying this incredible experience, you can take a comfortable elevator ride 750 feet back to the surface.

Although many species of bats call Carlsbad Cavern home, none is more numerous than the Brazilian free-tailed bat who make the upper most chamber, the Bat Cave, their summer home. These bats migrate from Mexico every spring to Carlsbad Cavern to give birth and raise their young in the protection of the cave. During evenings in the summer months, the National Park Service hosts a Bat Flight program where visitors can view the emergence of the bats from the natural entrance from the safety of an amphitheater overlooking the hole. What starts as a few bats fluttering out of the natural entrance, in a matter of minutes becomes a thick bat whirlwind spiraling out of the cave as hundreds of thousands of bats emerge into the night sky to feast on moths and other flying insects. The same process is reversed at dawn when the bats return to the cave to roost for the day. In late October or early November, the adult Brazilian free-tailed bats and their young head south for Mexico to spend the winter.