The Sequoia Underground: An Exploration of Crystal Cave

It's true that Crystal Cave in Sequoia National Park can hardly be described as a wild cave. Since its discovery in 1918 and its development as a park attraction in 1940, the cave has been visited by more than a million people. Dynamite was used by workers to widen passageways, and besides the lighting and pathways, there was a generator, and underground bathrooms. And yet there is still something wild about the cavern. Because it was discovered by park personnel and protected from vandalism from the beginning, the cave presents some wonderful examples of speleothems (cave decorations). The cave has a total of 2.42 miles of passageways (the third largest in California), but only a fraction ever receives visitors. The rest remains an underground wilderness.

The cave is an integral part of our field studies course on the geology of Sequoia and Kings Canyon National Parks. We paid a visit this last weekend and made the cave our first stop. Our tour began with an orientation on White-nose Syndrome (a fungus that kills bats), and sterilized our shoes. We then started down the half mile trail to the cave entrance.

The trail itself is a pleasure, and a good introduction to the local geology. The rocks are part of the Kings Terrane, a group of metamorphic rocks that formed in a shallow marine setting in Triassic and Jurassic time (around 200-150 million years ago) with some parts possibly older. The rocks formed in the Pacific Ocean and were accreted to the western edge of the North American continent as the mass of continental crust entered into the vast subduction zone that was consuming the ocean crust. The collision and subsequent invasion of the rock by molten granite caused the silt, sand and lime mud to become schist, quartzite and marble. It is in the marble that we find the caverns forming.

The trail provides a nice view of the marble cliffs. Permanent springs cause Cascade Creek to flow year round, providing a cool stretch of trail on a hot day and some beautiful small waterfalls.

Soon we reached the entrance to the cave and met our guide. The cave is administered by the Sequoia Natural History Association and is generally open for tours from the early spring to late fall.

A cool breeze was blowing out of the cave. The temperature is controlled by the average year-round climate, so the cave is relatively cooler in summer, and warmer in winter. Although the darkness of the cave provides little in the way of food, a number of animals do live in the cave, including a number of species of bat, and small arthropods like spiders, isopods and pseudoscorpions.

Entry into the cave is controlled by the famous spider-web gateway. I remember vividly seeing that gate when I visited the park for the first time as a child in the 1960s, and I remember the gate (and the underground bathrooms) the best.

Given the number of visitors, it's amazing that any cave decorations are left. It's to the credit of the park service and history association workers that so little damage has been done, although plenty of bad things have happened (the park service actually allowed self-guided tours for a brief time with disastrous results). The improvements to the pathway have actually meant that some of the stalactites and stalagmites have begun healing from previous damage, as evidenced by the pure white calcite on some surfaces. Dust from tramping feet and smoke from torches left many features a dingy yellow or brown color.

We passed some beautiful stalagmites on the floor of the cave, and then moved into the Junction Room, which was filled with the sound of babbling little brook. The cave is still very active, as it diverts a nearby creek underground. There are several levels to the cave, developed as the local canyons outside have gotten deeper, causing the rivers inside the cave to erode downward. There are numerous benches and terraces attesting to the former presence of higher level streams.

We moved through the Curtain Room, where a profusion of cave curtains and draperies hang from the walls and ceiling of the cave. They are out of reach of vandals and are thus largely unbroken.

The Dome Room contains one of the cavern's most famous features, the Fairy Pools. The rimstone pools and soda straws are actively forming (and recovering slowly from vandalism).

A zoom onto the soda straws (below) shows the water droplets on the ends. In these conditions, soda straws can grow at maybe an inch per century.

The unbroken draperies show an intricate structure.

The Marble Room is the largest in the cave, extending for more than 100 feet, with the ceiling 30 feet above. It is an amazing sight. It's also where they turn out the lights and let explorers get a feel for total darkness. Some people really don't like the sensation.

There are nearly 300 known caverns in Sequoia and Kings Canyon National Parks (Boyden Cave, another developed cave, is just outside the park boundary). The caverns include Lilburn Cave, which at 28 miles of passageways is in the top twenty of the largest caves in the nation. Most of the wild caves are remote, and their locations are kept secret for obvious reasons. Clough Cave was known a century ago as a beautiful cave festooned with thousands of stalactites. When the cave was publicized, the speleothems started to disappear, and today Clough Cave is pretty much a featureless hole in the ground. Several vandals were caught by park rangers in 1997 stealing some of the last artifacts in the cave. What a crying shame.

In the meantime, if you ever visit Sequoia or Kings Canyon, be sure to give the cavern a look. You won't regret it!

Where are the Ten Most Incredible Places You've Ever Stood? My Number 4: What is it like to be the first person ever to see a cavern?

Can you imagine flashing a light in a dark corner of a cavern, knowing that you are the first human being ever to lay eyes on the formations? I haven't had that privilege in my life, but I have found two or three places where I can imagine what the experience was like. Most of the caverns that are accessible to amateur spelunkers like myself have been long known and rather completely explored. Unfortunately, most of them have been severely vandalized, and the early use of torches for light left soot deposits on the formations. It is a rare treasure to see a cave where damage has not yet happened. Such caves in my experience include California Caverns near San Andreas, California,  Black Chasm Cavern near Jackson, California, and the subject of today's post, Kartchner Caverns near Benson, Arizona.

Many of the speleothems are still active; there are water droplets on many of the soda straws

The "Ten Most Incredible Places I've Ever Stood" series has been a series of hard choices. This one made the list because of the shock and the awe, the way the cavern made my jaw drop as I stepped in. It is an experience unlike any other that I've had while underground. There is a difference between even a well-protected cave, and one in which whole areas have never been touched by a human being. The floor of one of the large rooms was covered with mud, and it was clear from the trackway above that only one trail through it was ever made, in order to put in a light source. The rest of the room remains as it was discovered.

How incredible is it that some of the soda straws that fell are still standing in the mud?

The discovery and visitation of any cave causes irreversible changes. Kartchner Caverns were discovered on private lands in 1974 and the people who found them were concerned about preserving the original cave environment. The cave was at nearly 100% humidity, and opening it to the desert environment would have dried it out. Such changes in humidity can adversely affect life in the cave and stunt the growth and development of speleothems (cave decorations like stalactites and stalagmites). And yet the caves were spectacular. Was there some way of preserving the caves while making them accessible to the public?

The discoverers hit on an audacious solution. Through a series of delicate and secret negotiations, the owners of the land agreed to sell the lands containing the cave to the state of Arizona to be developed as a show cave, but to be developed in such a way as to preserve both the features and the climate inside the cave (many of the legislators didn't know what or where the park was when they voted for it). They preserved the humidity of the cave using a series of unique airlocks. Pathways were constructed with a minimum of disruptions to the original configuration of the cave. It took 25 years from the time of discovery to the opening of the park to the public in 1999.

There was one catch. Nothing goes into the cave with the visitors. No food, no water, no backpacks...and no cameras. As you might expect, I live for photography and this for me was a hard restriction. In 2005, though, I got the opportunity of a lifetime: as part of a fund-raiser for the park's foundation, they had a photography day, and the National Association of Geoscience Teachers made arrangements for us to take part. I was going to be given access to the cavern to photograph to my heart's content. To be sure, I had to sign a waiver of commercial rights, and the images that you see in this post today are protected and cannot be sold or used in any way.

Perhaps the most incredible stalagmite/column I've ever seen

What a wonder it was to step into a cave that appeared the same as it was on the day of discovery! The airlock closed behind me and although the temperature was only 78 degrees, it felt much hotter because of the intense humidity. The passageways were dimly lit and it took some time to develop my night vision. But moment by moment the cavern came into focus. It was simply stunning.

I wandered from passage to passage lost in the moment. It was nice not having a guide (staff were stationed throughout the cave to answer questions and keep an eye on things), but it was also nice to be exploring a pristine cave knowing I wasn't doing major damage just by being there. Exploring a newly discovered cave means leaving muddy footprints and accidentally destroying delicate formations underfoot, or leaving trails in the mud. I remember thinking that the experience was something like being in a museum, but I thought that in a good way: the resource was being protected, and yet hundreds of thousands of people could see and enjoy it. 

Some marvelous "helictites", otherwise known as stalactites on LSD.

Although I can't be mistaken for a professional photographer, I learned long ago that photography in a cave is always tricky. There is no "natural" look to a cave except total darkness, but a camera flash steals perspective and washes out delicate differences in color and shading. I used the ambient lighting to maintain some depth to the photos. That meant standing very still for longer than usual exposure times (tripods weren't allowed at the time). 

Flowstone refers to speleothems that result from water seeping out of cracks in the walls of a cavern. Over time gigantic mounds build up that resemble ice cream sundaes. Kartchner is full of spectacular examples.

I'm not sure what to make of the features below. There are some nice soda straws, which are so delicate that they are the first to be broken off in unprotected caves. The spiky things are the beginnings of helictites, which tend to ignore gravity, growing instead under the influence of water pressure from the interior of the "confused" stalagmites.

Below, one can see a spectacular column in the foreground, and some marvelous draperies in the upper left background. None of the features were broken off, and none were vandalized. I can barely describe what it is like being in such a place. Every minute in the cave was precious. I know there is an argument about worrying over technology in situations like this, and that one needs to live in the moment, reveling in the experience of being, but I actually find caves disorienting. Despite all my orienteering skills on the Earth's surface (and people tell me they are formidable) I get lost in caves. I can't remember one room or one decoration from another. Photographs keep me centered, and keep the memories of the moment alive. And I can share them!

I passed a stunning wall of draperies. Time was beginning to run short and I would be needing to leave this fantastical world for the surface before long. I was sweating, dehydrated, hungry and tired. It wasn't difficult getting around, but the humidity gets to you eventually, draining your energy. I started to head for the exit chamber and the airlock to the outer world.

There was one last close-up of a moist, almost glowing surface of some flowstone, and then I was out the door to the world of light and fresh air. The contrast was shocking. Caverns are incredible places, but they aren't really a human environment. I can understand how the first explorations of caverns could awaken our ancestors to the ideas of shadow-worlds with their demons and nightmares. Hell was presented as an underworld of fiery pits and eternal torment. But in a different context, caverns have been a place where dreams come alive. I think of the spiritual awakening of an initiate in a deep cave thousands of years ago encountering the drawn images of animals and people on a cavern wall seeming to run and play in the flickering light of a burning torch. Wandering through a pristine cave in the present day brings us face to face with a fascinating world that is not completely apart from us. The deep hidden parts of caves may not be a human environment, but much of our early spiritual and cultural development derived from living and exploring the outer edges of the underground environment. Caves are places where magic seems possible.