My Rational Voice says calmly, You could die here. Don’t mess up. Thanks, Rational Voice.

On October 22, the San Diego Union-Tribune published a story with the headline, “Woman rescued after being stuck in cave in East County for 16 hours.” The story related that the woman, 29, was “in an area known as Thunder Canyon Cave — made up of openings formed between piled-up boulders — off McCain Valley Road north of the rural community of Boulevard. The woman was ‘traversing a narrow opening’ in the cave with friends…when she got stuck” in what the story called a 12-inch gap. Her friends couldn’t budge her, so there she stayed for the next 16 hours, until a gaggle of agencies teamed up extricate her. The article concluded with a list of reminders from Sheriff’s Lt. Jeffrey Ford for those who go caving. But there was one reminder he left off the list, one I am happy to provide: Maybe don’t enter Thunder Canyon Cave.

Frankly, I was surprised that the article was as precise as it was about the cave’s location. There are multiple ways in and out of the cave, but those who know them consider it rude to ask precisely where they are. You have to be invited. It’s not that cavers are territorial, the way some surfers are said to be, jealously protecting their secret spots from outsiders. It’s more that we want to protect our access. It’s why we regularly pack out any trash we find in the caves, and why any mention of the place must come with a strongly worded warning. Thunder Canyon Cave is a technical cave; it is not meant for hikers or tourists. Entering the cave comes to extreme risk in the best of conditions. There are sections where you must rappel down a rope, where mistakes not only endanger your own life, but also risk the safety of your team.

Searching online for information about the cave yields little about where exactly it is, and lots about near death experiences, related by people who have gotten stuck and then gotten rescued. But rescue is by no means certain. There is the very real possibility that getting stuck or even slightly injured will mean death — hypothermia taking you down before help can arrive. And despite cavers’ attempts at secrecy, I would say that the vast majority of people entering Thunder Canyon Cave are unqualified to be there — meaning, they would be unable to reverse course should they find themselves unable or unwilling to go forward. To reverse your path through the cave means you must have the equipment and experience to climb a rope up vertical shafts. In short: this publication and the author disavow any mishaps you may bring upon yourselves or your friends should you decide to ignore your better judgment and go spelunking. You know, the way I did.

Now that you’ve read my disclaimer, I can tell you that about an hour east of downtown San Diego lies one of Southern California’s greatest adventures, if your idea of adventure involves risking your life underground. It’s funny: I don’t think of myself an “adrenaline junkie,” but my sport of choice does have an obituary-type section in many online groups. Lately, I have been thinking about that. I’ve realized that as you get deeply immersed in something, it is usually inevitable that you lose most of your perspective about the value of, or even the motivations behind, the thing in which you are immersed. Especially inherently risky things like rock climbing or caving. Why do I do this? But sometimes, life finds ways to restore that perspective. And that’s how you end up writing a story like this one.

The epic rains of 2022/2023 inspired my caving buddies and me to pay Thunder Canyon Cave a visit; we knew that all that water would make the cave live up to its name. The homestead or ranch that is near the elusive cave stands on the edge of a slope that drops down to the open desert that leads out to the Salton Sea. I used to imagine that the discovery and naming of the cave was done by children playing near the ranch, but we now know that it got its name because when it is in “peak flow,” the sound of water underground thunders up the canyon. We wanted to get close to the thunder.

Descent

As I wait for my turn to enter the cave, I find myself thinking about taking my son through. Oh, hell no, the Rational Voice says internally. I look into the hungry black hole that is the cave’s mouth, and it feels something like the entrance to a tomb. It is obviously way too dangerous to allow my children to enter. And as I wait, the Rational Voice asks me, You’re their father; if it’s too dangerous for them, what are you doing here? It’s a fair question.

You don’t take a first step into Thunder Canyon Cave. You make a first descent, hanging onto a rope. As I lower myself down, I can hear the water roaring below. Mud and grit and water from the rope, which is being wrung out like a dirty dishrag by my death grip on it, splashes all over my chest. Then my rain jacket gets caught in the rope. Or rather, it gets caught in the belay device attached to the rope. (The device provides friction, and so regulates my rate of descent.) The device has sucked my jacket into itself, and I am temporarily stuck hanging over a pool of water about fifty feet below. I have no idea how deep the pool is. It occurs to me that my hands are getting cold. Just then, the Rational Voice says calmly, You could die here. Don’t mess up. Thanks, Rational Voice.

The epic rains of 2022/2023 inspired my caving buddies and me to pay Thunder Canyon Cave a visit; we knew that all that water would make the cave live up to its name.

Luckily, I am just over the lip of the first drop, within reach of Bobby, my buddy who is the last going through the cave mouth.

“Bobby. I got a situation here.” Even as I say it, I am in self-analysis mode, noting the lack of emotion in my voice. I sound like an airline pilot, informing the passengers that one of the engines seems to be on fire, but not to worry, just a little heads up. It’s curious.

He peers down, quickly assesses said situation, grabs my hand, and pulls me up just enough to unstick my jacket from the belay device.

The Rational Voice asks earnestly, What would have happened if Bobby had not been there? My imagination instantly spins out the most likely scenario: I would have used one hand to try to unstick my jacket from the belay device. As I did this, my other hand would have slipped, and I would have fallen down, down, down into the dark abyss, bouncing off the bumpy walls until my broken body splashed into the pool below and sank unceremoniously to the unfathomed bottom. Thanks to Bobby, I am able to unstick my jacket without dying, but now there is a large hole in it.

What a grave is like

When I reach the end of my descent, I find that the usually flat, dry room — I’ve been here before, a number of times — is flooded with three feet of water. Further, a six-inch fountain of water is shooting out of the wall and then free-falling twenty feet. My friend Mike has already plunged through the waterfall and I can hearing him shouting for me to follow, so I plunge after him and begin the crazy scramble through the cave; it goes up, down, and around dozens of twists and turns. In some places, I am doing moderate rock climbing without a rope. In others, I am squeezing through fissures so narrow I have to remove my backpack and bring it through behind me. The surprisingly warm rainwater ups the intensity of the journey in terms of unknowns and their attendant risks, but I press on behind Mike. I trust Mike with my life, literally.

The waterfall left me instantly soaked, and therefore cold. Time has just become a factor; there’s no need to panic just yet, but we do need to reach the exit before the cold starts to interfere with our functionality. We could always reverse our path — really, we could; we have the equipment and we have the experience — but the Rational Voice would surely raise sound objections to an attempt to ascend 60 feet up a wet rope with water spraying on us. Besides, the cave is passable so far, and so we move forward as quickly as we can through the wild, wet labyrinth.

We pause when we reach The Cathedral Room, at the end of another rope drop. It is by far the largest open space in the cave; perhaps 80 feet from the floor to the wedged-boulder roof above. Someone brings up the way that aquarium filters can clog and then suddenly unclog, releasing a wave of debris. We all visualize a flash flood. You could drown.

I am third in line in our four-person team. The two people ahead of me, Mike and his girlfriend Kelly, are moving fast down the winding path, and after about 50 feet, they make a sharp right, leaving me alone to wait for Bobby to finish his descent. There is no sound, save for the water roaring under my feet, and when I turn off my headlight, I am surrounded by utter darkness. I wait in the cave, marveling at my unseen surroundings. Sensing an opening, the Rational Voice instantly strikes up a conversation: You know, this must be what the grave is like. In fact, this probably will be your grave.

Well, it certainly could be, if I mess up. But I’m not gonna mess up.

The Rational Voice goes quiet, not even bothering to say anything about famous last words. Then Bobby catches up.

The slow brain bleed theory of motivation

As I was thinking about how to tell the story of me and Thunder Canyon Cave, I found it hard to explain my motivation. Why go repeatedly to a place that is well known to be extraordinarily dangerous? Yet surely, that must be part of the story. Why? Was I dropped on my head as a child?

As it turns out, yes I was — sort of.

You don’t take a first step into Thunder Canyon Cave. You make a first descent, hanging onto a rope. As I lower myself down, I can hear the water roaring below.

As I wrote this account, I kept thinking about those of us who take part in dangerous sports for fun. I did some reading, and it turns out that there are a few common traits among us risk takers. The primary pattern I noticed was that many of the people who do (and write about doing) the most outrageous things — things like climbing giant cliffs without ropes — have also written about suffering depression and concussions. There seems to be a part of the brain that can get shut off when you suffer brain injury. The medical term is “slow brain bleed,” and the short description is that if you get dropped on your head, you can wind up with a slow seepage of blood and fluid in the skull that does things like cause depression, kill normal fear reactions, and make you suffer mild bi-polar-like symptoms.

My buddies and I are all bold. We have shared many adventures. All of us have been knocked unconscious at least once. But I’m not going to speculate as to their motivations. All I know is that in 5th grade, I cracked my head open in a snow sledding accident, and that I’ve always been a little edgy and have what some say is an unusually calm demeanor in high-stress situations. So maybe I’m down here because my bleeding brain has killed my normal fear reactions. It’s not that I’m seeking the thrill of courting death; it’s that I don’t know enough to be scared — Rational Voice or no Rational Voice.

As I continued reading about other adventure athletes, people who climb without ropes, I learned that many of them eventually take one risk too many. Some fail to solve their problems by taking the risks they do, and wind up taking their own lives. Most don’t seem to have read about brain injuries, or about how they can “re-wire” the brain. They don’t seem to know that it may be these brain injuries that make our minds so full of dark mental chatter that sometimes, we obsess about the grave, or take risks that some reckless to other “normal” people. The Irrational Voice drowning out the Rational.

As for me, I learned that first and foremost, I do these things that are really hard and dangerous because they make everyday problems seem tame and simple — not because I want to get hurt. (After you’ve watched a rock the size of an elevator plummet past you as you cling to the face of El Capitan and explode on the spot where you camped last night, road rage over stalled traffic just seems idiotic.) But because the mental chatter is still there, it has to be tamed. The adrenaline that comes with risk is a strange reminder that we are alive, and the near-death experiences that come with things like Thunder Canyon Cave or rock climbing can remind people with this problem that we really do want to live.

The book in the bottle

Another part of the motivation is the whole Star Trek thing: to boldly go where no one — or very, very few — has gone before. People have inhabited the area around McCain Valley in the In-Ko Pah mountains for approximately 10,000 years. But there is no way any of those ancient Americans would have been through these passages, because Thunder Canyon is a climbers’ cave. Deep in its bowels, there is the caver’s equivalent of a summit register — a book wherein mountaineers leave their names and date of ascent. Thunder Canyon Cave’s version is a book in a bottle, hanging from a string. A bottle? The first time I saw it, I found it hard to imagine enough water coursing through the cave enough to dampen that suspended book. Now I know better; now I know that in rainy years, no corner of this cave is safe from the water that literally thunders through its underground passages. On my first trip through, I came across formations I mistook for petrified wood, so closely did they resemble thick, twisting tree roots. I was baffled: how could tree roots get this far down, through this much rock? But they were not wood; they were stone, their crazy curves carved by centuries of rushing water.

Inside the register are names and dates left by people who have passed through. My name is in there at least six times, and each time I go through, I feel the sense of an enormous passage of time. How long does it take rain to shape stone? I also sense doom. At the bottom of the cave, it is common to find the remains of snakes and tarantulas that have gotten trapped in there, perhaps lured by the smell of water in the desert into this patch of deadly eternal darkness. So Thunder Canyon Cave is a tomb — but this time through, the cave has been flushed clean of all its corpses.

During summer trips to the cave, we usually go at night. The approach hike in is along a sandy trail, downhill going in and a long uphill slog going out. At night, the desert is teeming with insect and animal activity, and Thunder Canyon Cave is no exception; at night, there are bats and spiders aplenty. We always go through in a group of at least three, and if one of our party has never been through, we usually ask that person to lead the way. This is because it is both exciting for them to explore and fun for us to watch the fear that often registers on their faces as they try to find the right way. It’s a bit easier than it used to be, as there are now some directional arrows painted on the walls, the work of rescue teams that have had to hoist out hapless parties stuck deep inside. But even with the arrows, there is a plethora of dead ends and risky drop-offs; and even after you’ve led the way a half dozen times or more, you have to be careful about not going the wrong way.

Kelly, who is the least experienced of the team, has a moment of panic when Bobby and I consult our maps. We are not lost, just trying to see on the map where the waterfall is marked. But she mistakes our curiosity for confusion about which way to go, and becomes visibly distressed.

Going the wrong way doesn’t mean doom, of course; it just means retracing your steps to find the correct path. Unless you fall, or make a mistake at the wrong time, the Rational Voice points out, and I imagine my headlight dying, and the voices of my friends getting farther away. The Voice has a point: in some passages, if you were to botch the job of making your way through, and slip and fall, you might get stuck in such a way that your body would not be retrievable. So, you don’t fall. It’s a little like free-climber Alex Honnold in the movie Free Solo, gripping the sheer rock face of El Capitan and facing certain death if just one thing should go wrong. There are places as you pass through the cave where you simply cannot make a mistake. But of course, mistakes happen: in Free Solo, Honnold gets injured twice in the run-up to his death-defying climb. The Rational Voice presents, in great detail, a mind movie about the variety of ways I could die inside Thunder Canyon Cave — the most obvious being a slip resulting in a compound fracture.

The cold grip of fear

As I mentioned, we are moving fast. Normally, we would spend two hours or more exploring the cave, but now we are just racing. We are cold, and speed is safety, as they say in the mountains. But haste also makes waste. I caution the team to keep their bodies away from the rock walls whenever possible, because the rock leeches the warmth out of your body quickly. We encounter another waterfall, and realize we must either run through a drenching shower or turn back. Kelly, who is the least experienced of the team, has a moment of panic when Bobby and I consult our maps. We are not lost, just trying to see on the map where the waterfall is marked. But she mistakes our curiosity for confusion about which way to go, and becomes visibly distressed.

This increases the sense of urgency and we increase our pace. The Rational Voice says, You know, we don’t know if she can climb back up that rope, through a mist of water, and if she loses her cool and starts to freak we are going to be stuck in here...forever. This time, I have to grant the Voice’s point. That means making our way back to the entrance is no longer an option; we are now committed to going forward. And we do.

But now, instead of the Rational Voice yammering in my skull, I find my imagination briefly playing out the scene of the four of us in there, forever. Perhaps our remains would be found, many years later. Perhaps not. I realize what this is. This imagination is irrational fear. Rational fear keeps you alive: it is wise to be afraid of falling from great heights. It is not wise to imagine your equipment breaking or being stuck for ten thousand years. Irrational fear is also what causes panic. My ability to separate rational fears from irrational is a byproduct of many years spent rock climbing. The rational fear is that if we are too slow or get stuck, we could all die of hypothermia. The irrational fear is that we are lost inside the cave.

Here’s the thing about panic: it’s contagious. So I seek to quell it. As we move toward the final and most dangerous passage, I start speaking calm words of encouragement — to myself and anyone in earshot. “We are almost out. This is the last bit. All easy from here.” Kelly does not panic. She does remarkably well.

Exit

But of course, it’s not really “all easy from here.” The final section is called “The Dread Chimney.” It’s been the scene of a number of near-fatal mishaps that have required full-on rescue operations. The Chimney is a twenty-five foot section that starts at about 18” wide and quickly pinches down to a slot so narrow that you cannot turn your head. My climbing helmet makes it a tight fit. You start in, and then you must invert sideways and slither across a wobbly wood plank. Twisting or getting your feet tangled will quickly have you stuck, exhausted, and rapidly dying of hypothermia. It can be 110 degrees outside Thunder Canyon Cave, but down here, the rock walls are about 73 degrees. Getting stuck against them brings death. Remember Jack in Titanic, freezing to death as he hung onto that door? This sets the same sort of clock ticking, just with a few extra hours added.

Mike goes through. Kelly goes through. Bobby goes through. I am last. Before I start in, I pass through the small back packs we carry, the ones that contain extra lights, food, and vital equipment. (If you are in a cave with one belay device and you drop it, you will put yourself and your entire team in grave danger. So we observe the rule of redundancy: if you cannot survive without it, bring two or three.) Then I pause and look back. The team is waiting for me, but I want to enjoy the mad profundity of the moment. I turn my headlight off and do the first half of The Dread Chimney in a darkness as deep as the grave. This has the desired effect: my heart races. The darkness makes me feel something like fear, something like what I think it is other people must feel. Then I turn the light back on and execute the crux section without dying. This time, the Rational Voice says. You get to live, this time. But if you sit at this table long enough and get dealt enough hands, sooner or later, The Dealer wins. Well, sooner or later, the Dealer always wins. The trick is to make it as later as possible — while still living life.

Now we really are nearing the end; now everything really is easier. We can feel warmer air, and the thundering sound of the water is more distant. We point these things out to Kelly, and she leaves her fears in the darkness behind us.

I haven’t been back to Thunder Mountain Cave since that trip. I have a sense that I will never top that experience, not by climbing or caving. But when I do think about going back, it’s because I want to further explore another sort of labryinth, one that is entirely interior.