Holes in the ground are charmed. Like finding a cave in the sea, they are a deeper darkness. They pull our imagination. They entice us with mystery, the unimaginable and
the unknown. So it was for one teenager in the late 1800’s while riding his horse through the Chihuahaun Desert of the New Mexico Territory. Young Jim White stopped to watch as a plume of bats boiled out of the ground obscuring the flaming sunset. No young man can leave a hole like that unexplored! Indeed the exploration would consume many years of his life.
As simple as these circumstances were, this serendipity encounter would lead to what we all know today as Carlsbad Caverns. A national park and arguably the most magnificent show cave in the United States. For those who have visited the caverns, the dreamlike imagery is burned into our mind’s eye forever. Consider the awe of gazing upon this magical space for the very first time!
Texas contains at least 9,000 caves, caverns, sinkholes and springs. More than 100 Texas caves stretch for more than 900 feet and Honey Creek, which is still being explored, is the longest at 20 miles. Texas has its share of bats too. 100 million Mexican free-tail bats live in two dozen Texas caves and it is estimated they consume 6,000 to 18,000 metric tons of insects a year in Texas. That’s a lot of bugs!
Forming caverns out of solid rock is a geologic process, meaning it usually takes longer than a human lifetime to unfold. Grasping the significance of this arc of time is an extraordinary mind tease. A humbling experience. A reminder that we are but a small part of Great Nature.
There are various ways caverns are made and they can be created out of various types of rock. It may involve a combination of chemical processes, erosion from water, tectonic forces, microorganisms, pressure, and atmospheric influences. That said, many underground caverns are formed in limestone by a process of dissolution.
For dissolution to occur, there needs to be water, time and chemical reactions. It can start in the smallest of cracks or joints in a limestone formation and, with enough time, can end up channeling powerful underground rivers. Rainwater seeps into the ground. The groundwater eventually becomes charged with carbonic acid and other naturally occurring organic acids, which eat away (dissolves) the softer limestone from harder rocks.
Oh, what a thousand years can do! 800 feet below the surface you are slack-jawed, eyes bulging like a frightened horse . . . there before you is a most gaping opulent chamber, glowing with a mineral kind of heat, banded with surreal ceiling-to-floor columns; as inaccessible to most of humanity as the dark side of the moon. Yet there you are—so far from anywhere, in the middle of silence and unspeakable beauty.
But there is science behind that beauty. Secondary mineral deposits (calcium carbonate) often adorn the inner regions of a limestone cavern, producing strikingly elegant formations. Flowstones, stalactites, stalagmites, helictites, soda straws and other exotic formations are made like this. This haunting underground furniture requires many years of slow precipitation to develop. The most majestic of these underground caverns are considered show caves. Those without bling are known as “wild caves.”
Cavernous topography comes with its own challenges. Sometimes water is syphoned away into underground channels, leaving the earth at surface parched and dry. Not a good place to build a farm.
Streams may disappear underground several places and spring up again in different places. Now you see it, now you don’t.
Because of increased permeability, cavernous areas do not filter water as well as normal aquifers. Water running through cavernous country is just as easily polluted as surface rivers and streams.
Sinkholes can be prevalent and these present potential problems for everyone. Sinkholes can develop gradually as surface openings enlarge, but progressive erosion is frequently unseen until the roof of an underground cavern suddenly collapses. A recent example is the cavern-sinkhole that swallowed part of the collection of the National Corvette Museum in Bowling Green, Kentucky in 2014.
Here in Texas, the Edwards Plateau is one of the largest yet understudied cavernous regions in the nation, and there are over 130 caves that have been discovered within this area with many more yet to be fully explored. There are seven underground wonderlands in particular which draw people from all over.
Natural Bridge Caverns are nestled between San Antonio and New Braunfels, this is the largest commercial cave in Texas. The system is always open with public tours and many special events throughout the year.
Cascade Caverns are another impressive underground experience, complete with a constant temperature of 68 degrees and a 100 foot water fall. Cascade caverns is found outside of San Antonio near the town of Boerne.
Wonder World is a Texas State Historical Site and the only earthquake formed cave in the nation. Lying against the active Balcones fault line, you are taken into the cave by descending through the middle of an ancient earthquake. The park has several other attractions for family activities and is located in the middle of San Marcos.
Inner Space Caverns will wow you with an other-worldly feel among its spacious underground chambers. These caverns were discovered during the building of Texas’ first highway in 1963 and parts of it are still being discovered to this day. The caverns are located 20 miles north of Austin off of I-35.
Caverns of Sonora are listed as a Natural/National Landmark. With 90% of its geological features still forming it is one of the most actively growing caves in the world. Originally explored in the 1950’s, today only 2 miles of the 7 miles of passage is open to the public. The Caverns of Sonora are located just 8 miles west of Sonora Texas off of I-10.
Cave Without a Name is also still growing and sports six dramatic rooms filled with artful lighting and wondrous underground formations. Like so many of its counterparts, the temperature underground is a pleasant 66 degrees year round. It’s located 12 miles outside of Boerne, Texas.
Longhorn Caverns are one of the few river formed systems in the state and it’s my favorite because it is also a State Park with a CCC heritage. This is one of the most visited caverns in the state. There is an interesting history that dates back to the Comanche Indians. During the civil war, the underground passageways were a Confederate stronghold where gunpowder was made in secret. You can find the caverns in Burnet County, Texas, just six miles west of U.S. Hwy. 281, on Park Road 4.
Natural beauty cannot be replicated. No artist can match its genius. Through the forces of nature and the slowness of time, it’s as if history and eternity are being made at the same time—and we, for the brief time we are here—may gaze upon these miracles with wonder. You are surrounded by caverns . . . and your time is short!