March 23, 2015 — Today is a beautiful day – it’s sunny and 80 degrees in the desert, but we’re spending the day in a cave system where the temperature is a pretty steady 56 degrees no matter what the weather is outside – what are we thinking?!? Actually, we’re thinking that Carlsbad Caverns National Park is a pretty awesome place to spend a day!
Just like Big Bend NP and Guadalupe Mountains NP, the two nearby national parks that we have visited in the last two weeks, this area, too, was covered with an ocean some 250 million years ago. Sponges, algae, ammonites, and other living organisms built a gigantic reef along the shores of a broad bay; and eons later when the sea receded, their lime deposits were buried beneath sedimentary material.
A couple hundred million years later, tectonic plates beneath this area pushed up what we now call the Guadalupe Mountains, under which we find the Carlsbad Caverns. [Incidentally, Guadalupe Mountains NP and Carlsbad Caverns NP are only about 35 miles apart.]
This cave system was formed as water containing calcium bicarbonate seeped into the limestone deposits from the former marine reef. The soft limestone began to dissolve, aided by sulfuric acid which came from oil and gas deposits beneath this part of the earth. Over millions of years, great rooms and passageways were created out of the limestone, and it is these that visitors to the park walk through. Calcite from the limestone contained in water seeping through the cave roof accumulates in the caves in the form of speleothems. This is the scientific word for the mineral deposits we find in the caves, including: stalactites – these cling tight to the ceilings; stalagmites – you might trip over these on the ground; draperies – thin, wavy sheets of calcium hanging downward; soda straws – long, thin cylindrical hanging deposits; popcorn – small, knobby clusters of calcium; and columns – formed when a stalactite drips so much onto the stalactite that the two come together.
More than 30 miles of cave pathways have been mapped; but only a few of the passageways are paved, lighted, and open to the public. Visitors typically take a self-guided walk down from the Natural Entrance, descending a steep 750 feet into the caves; that’s the first mile of walking and speleothem viewing. In the main chamber, the Big Room, various formations are named and lighted, and here a giant loop trail covers another couple of miles, passing by many other formations. It’s remarkable how huge this this underground space is. The Big Room is nearly 4,000 feet long, and 625 feet wide; approximately 14 football fields could fit inside it! We walked and photographed all through the self-guided sections, ate our picnic lunch in a small underground lunchroom, and then took an afternoon ranger-guided tour of another, more scenic area of the system; the Kings Palace.
I would be remiss in writing about Carlsbad Caverns without mentioning the bats. We were here a bit too early in the year to see this, but every evening from early spring through October, hundreds of thousands of bats fly out of the cave’s Natural Entrance en masse each night and spend the night outside the cave eating insects. By day the bats are inside the cave hanging around [sorry, I couldn’t resist] and making guano.
Understandably, this phenomenon would be quite a sight, and many people gather in the amphitheater each evening to watch the event. And in fact, it was this great bat flight spectacle that drew attention to this place in the first place. While there is evidence that Native Americans had ventured into these caves 1,000 years ago, little is known about their experiences here. Then in the 1800s, drawn to these enormous swarms of flying bats, locals re-discovered the caves. Enterprising guys that these early cavers were, they mined the huge deposits of bat guano and sold it as natural fertilizer from 1902-1958. During this time, a guy named Jim White became fascinated by the caves, explored them more fully solely by the light of a lantern, and ultimately drew attention to this marvelous place.
In 1923, Carlsbad Caverns was proclaimed a national monument, thus preserved and developed for all to see. Since that time, the park has expanded, converted to a national park, become a World Heritage Site, and now includes more than 100 other caves and 100+ more miles of passages. Today cave scientists from all around the world come here to explore and learn and discover the secret life and mysteries inside caves. Promising developments in cancer research are coming out of the caves here as microbes have been discovered that produce enzymes that are capable of destroying cancer cells. Who knew?
So it seems some really good things happen when people go down and into caves. And we really enjoyed our day, even if it meant we had to wear a jacket in the desert!