Limits of the Known

by David Roberts

  Caving has never inspired the kinds of coordinated national campaigns that seized Himalayan mountaineering in the 1950s, when all-star teams from France, Switzerland, Italy, Germany, Austria, Great Britain, and the United States competed to claim the first ascents of the fourteen highest mountains in the world. But cavers are prone to a kindred passion fueled by nationalistic impulses. In particular, the French corner on the world’s deepest cavern, which long predated the pushing of the Gouffre Berger past 1,000 meters, stuck in the craw of several generations of America’s best cavers.

  In 1965 several of these zealots discovered a huge limestone plateau in the northern part of the Mexican state of Oaxaca. Within only three years they had plumbed the passageways of the Sistema Huautla to an impressive 2,007 feet—almost 400 feet deeper than Tears of the Turtle would attain in setting the U.S. record forty-six years later. Every caver who ventured into the wilds of Oaxaca agreed that Huautla had unlimited potential.

  During the next decade and a half, the quest for the deepest pit in North America was propelled by a close-knit band of enthusiasts based in Austin, Texas. They called themselves the Kirkwood Cowboys, after the road on which most of them lived in cheap housing, and jocularly referred to one another as “pit hippies.” By the 1960s, American mountaineering had gone mainstream, attracting generous sponsorship and public attention. The 1963 American Everest expedition, on which Jim Whittaker became the first U.S.-born climber to reach the summit, was supported by 185 donors, including NASA, the National Science Foundation, and the National Geographic Society. Its budget was $430,000—the equivalent today of $3,500,000. During the same years, the best cavers in America scrounged expedition funds by working menial jobs, and drove in beat-up trucks from Texas to Oaxaca on bone-jarring two-day jaunts.

  By the late 1970s, the exploration of Huautla had ground to a halt 2,750 feet below the surface, when the cavers ran smack into a huge sump—a pool of water that had collected in a long tunnel whose farther reaches could only be guessed at. As one of the Kirkwood Cowboys was fond of remarking, “A sump is God’s way of telling you the cave ends there.” One of the pit hippies, however, refused to give up. Bill Stone was a twenty-six-year-old working on his Ph.D. in engineering at the University of Texas. Six feet four inches tall, with a formidable physique, Stone was animated by a feral intensity that stood out even within the intense community of Kirkwood cavers. In March 1979, supported by two companions, Stone lugged scuba diving gear down to the San Agustin Sump, as the team had named the apparent dead-end pool. He was not the first caver to try to penetrate a sump with scuba gear (the French had made similar thrusts), but cave diving itself was still in its infancy, during an era in which an alarming number of its practitioners had come to gruesome ends in underground lakes far more accessible than San Agustin.

  Because the sump might require tight swims through narrow passages, Stone hauled “pony bottles” into Huautla—side-mounted air canisters he would drag along, in lieu of the back-mounted tanks usually employed in scuba diving. And because he was wary of a possible underground current that might sweep him toward a deadly waterfall, he tied into a rope that his buddies would feed out as he swam into the darkness. The agreed-upon signal that he had reached his limit would be three sharp tugs on the line. Stone counted on his teammates to pull him back to the chamber where they waited on the edge of the sump.

  This dramatic episode is recounted in two excellent books that cover the exploration of Huautla: Beyond the Deep (2002), by Stone, diving partner Barbara am Ende, and journalist Monte Paulsen, and James Tabor’s Blind Descent (2010). In the sump, things seemed to go wrong from the start. Because he carried no diving weights, Stone floated up to the ceiling of the spooky tunnel, and, lacking fins for his feet, he could not propel himself along effectively by swimming alone. Instead, he was reduced to crawling upside down against the corrugated ceiling.

  The air Stone lugged in his pony bottles allowed for a dive of at most thirty minutes. When he had used up a third of the air in his tanks, he realized it was time to turn back. But before reversing course, he flipped over to get a hard look through the crystalline water at the void that lay beyond. Then he tugged three times on the line.

  Nothing happened. As it turned out, there was so much rope drag underwater that Stone’s two teammates never felt the tug. They simply sat and waited for the signal, increasingly agitated about the elapsed time. Meanwhile, Stone frantically tried to reverse his ceiling crawl. He started to panic, gasping for breath as his lungs sucked in the precious air at far too fast a rate. And then his scurrying stirred up the sediment coating the walls and ceilings of the tube. All at once, he was floating blind in a silt-out.

  Remarkably, Stone fought down the panic and started a methodical crawl in the direction from which he hoped he’d come. And then the rope drew tight. According to Beyond the Deep, Stone’s partners decided it was time to haul him in. “We figured, hell, he’s been down there too long anyways,” one of them later said. “And so we started pulling.”

  By the time Stone resurfaced to join his belayers, the air in his last tank was down to 300 pounds per square inch—enough for three deep breaths. Despite his terrifying journey, Stone was ecstatic. At his farthest penetration, when he flipped over to gaze at the view beyond, what he saw mesmerized him. “The water was so pure,” he reported, “that the twin beams from [my] dim electric headlamps pierced down into the deep blue canyon and faded to black before revealing any hint of a bottom. [I’d] never seen anything like it.” Now he blurted out to his teammates, “Man, you wouldn’t believe it. That canyon is headed straight for the center of the earth.”

  Stone’s was not the last close call cavers would undergo on the Huautla Plateau. But to his dismay, his daring thrust failed to win over the more conservative veterans among the Kirkwood Cowboys. In their view, the San Agustin Sump remained an impenetrable obstacle. On a second expedition in 1980, the cavers focused instead on a nearby pit called Li Nita. That, too, seemed to dead-end in a sump. Once more, Stone hauled scuba gear into the abyss. This time he got through the sump and emerged in a massive dry canyon. A hunch that had driven him into Li Nita now caused Stone to drop his gear and scramble onward. Within minutes, he found what he was looking for: a survey mark scrawled in charcoal on the wall. Stone had linked Li Nita and San Agustin. And because the entrance to the former cave lay at a higher altitude, in one bold stroke Stone had stretched the Huautla system to a total depth of 4,002 feet.

  At that moment, Huautla became the third deepest known cavern in the world. At last, North American caving was playing in the big leagues so long dominated by the French. And who knew where the farthest reaches of Huautla ended?

  The San Agustin Sump, which lay below the Li Nita connection, still loomed as a formidable obstacle. It became Bill Stone’s obsession. But the decade after his breakthrough linkage with Li Nita in 1980 unfurled as a series of expensive and exhausting failures. By 1988, Stone had led or participated in a dozen expeditions to the Huautla Plateau, without any of them denting the depth barrier of just over 4,000 feet.

  Convinced that diving was not only the key to Huautla but perhaps to all the deepest caves in the world, Stone apprenticed with the master, Sheck Exley. Meanwhile, a born inventor, he spent months developing a radical new rig that he called a rebreather. Through state-of-the-art technology, Stone figured out a way to convert exhaled carbon dioxide into fresh, reusable air, even in the middle of a dive. But Stone’s teammates found the new apparatus complex and unwieldy. Almost none of them really trusted the rig. Stone became a lone believer crying out in the wilderness.

  In 1986, another pair of cavers, Carol Vesely and Bill Farr, hiked across the trailless Huautla Plateau searching for other cave entrances. Several hours into the forest, they stumbled upon a huge sinkhole. It formed a ramp that Vesely and Farr followed downhill until it abruptly ended in a cliff. But across the void, an opening in the hillside loomed. In James Tabor’s vivid description, “It looked li
ke a giant black mouth with ragged teeth, several stories high and wide enough to hold two Greyhound buses parked end to end.”

  In that moment, the two cavers discovered a system that would rival Huautla in promise. They called it Chevé. During the next three decades, Chevé would be pushed deeper and deeper, but the kinds of obstacles that had thwarted progress in Huautla stymied the best efforts of a legion of explorers. Stone himself would come to believe that Chevé had the potential to set records. The chief reason for his enthusiasm was the startling result of an experiment that sounds as if it came out of a high-school science lab.

  One way to determine the true extent of a cave system is to put a luminous dye into the water near the entrance, then wait hours or even days to see if the dye shows up in a current flowing out of a hillside miles away and thousands of feet lower. If so, the experiment proves the connection. In Chevé such a dye tracing produced a dazzling result. The colored water emerged, as its partisans had hoped, in a resurgence that lay a mind-boggling 8,354 feet lower. Cavers, however, are purists. Chevé didn’t count as the deepest cave in the world unless human beings could physically perform the connection.

  With the kinds of challenges that Huautla and Chevé posed, American caving became a more serious business than ever before. To get to the farthest reaches of a known passageway, teams had to spend days at a time underground. Inevitably, a logistical pyramid of supplies, not unlike the buildup of a Himalayan mountaineering expedition in the 1950s, had to be thrown at the problem. That buildup demanded the coordinated efforts of teams of cavers, most of whom served in the inglorious role of porters, to position a pair or trio of experts to push the system to new lengths and depths.

  It is worth pointing out the peculiar constraints that caving imposes on its pioneers, and that keep it “purer” as a means of exploration than above-ground exploits such as mountaineering and polar exploration. Airplanes and helicopters, of course, are useless in caving, except in rare cases to gain access to a remote entrance. If a person is seriously injured very far below the surface, saving his or her life requires a herculean and perilous effort by rescuers who must bodily carry and shuttle the victim to safety. Nor do radios work underground. Throughout most of caving’s current golden age, communication from the depths to the surface took place only by virtue of personal contact, as one teammate made the arduous trek back out to relay news of progress below. In recent years, cavers have laid telephone wires from entrances to the farthest passages, but so far the efficacy of such systems has proved uncertain. In general, in caving, there are no shortcuts to safety, no hopes of calling in a rescue, no substitute for the time-honored skills of crawling, slithering, climbing, and rappelling.

  Despite the blossoming promise of the two great Mexican cave systems after 1986, the Huautla Plateau began to seem a cursed place. In 1991, a moderately experienced caver inside Chevé set up his rig to rappel a 65-foot shaft. Somehow he failed to attach his rappel device to the rope. He leaned back and plunged into space. Despite a desperate effort to grab the rope with his hands, he was dead on impact with the talus pile below. Despairing of retrieving his body, his teammates buried him in the pit. A full year later other cavers, using a complex system of pulleys and ropes, were able to hoist his body to the surface.

  Meanwhile, Bill Stone kept tinkering with his rebreather. The advantages of the new rig were immense. As Jim Tabor explains, “A rebreather uses chemicals to ‘scrub’ carbon dioxide from a diver’s exhaled breath, which it recycles over and over, producing dramatically longer dive times. . . . A single standard scuba tank gives about twenty minutes of dive time at 100 feet. A rebreather can provide twenty hours—at least.”

  By 1987, Chevé had been pushed to 3,406 feet. But at that depth Stone’s team ran smack into a massive talus pile that blocked all access beyond. Cavers were willing to move rocks to enlarge passages, though the use of dynamite, once a staple of underground exploration, had been relegated to the limbo of overkill. But the breakdown pile in Chevé was far too daunting to dig through. Bitterly disappointed, Stone turned his back on Chevé . . . for the time being.

  The focus returned to Huautla. In 1994, Stone organized the most ambitious assault yet on the complex system. Partway through the expedition, divers finally cracked the San Agustin Sump, only to discover a whole series of sumps interspersed with dry “airbells” beyond. Despite such progress, delays and setbacks sapped the team’s morale. Then a sudden tragedy shook the expedition to its core. Ian Rolland, an experienced Brit who was a sergeant in the Royal Air Force, failed to return from a dive through two sumps separated by an airbell. It was Stone who found and retrieved Rolland’s body, in a formidable feat of solo diving and hauling. What killed the veteran was a mystery, and diabetes was suspected to have contributed to the man’s demise. But the grim event triggered a wholesale mutiny within the team. Bill Farr, who had co-discovered Chevé, announced, “There aren’t going to be any more dives. This expedition is over.” Stone disagreed, and tried to rally the troops with an appeal to their exploratory pride. “Three or four hundred years ago,” he said (according to Tabor), “ships would often lose fifty percent of their crew in the course of a voyage. The difference between us and them is that our society now places so much importance on life.”

  Stone’s intransigence, along with his determination to push Huautla at all costs, only further fractured the demoralized team. A caricature of their leader as a heartless fanatic and egomaniac circulated among the ranks. The upshot was that only Stone and his girlfriend, Barbara am Ende, along with a very small supporting crew, still had the nerve and will to try to push Huautla through the dangerous series of sumps that stretched beyond the San Agustin watershed.

  I met Bill Stone at a conference organized by NASA in the late 1990s. Its declared agenda was to give the country’s astronauts the benefit of the insights adventurers such as ourselves might offer about the future of exploration. The astronauts were privately scornful of us mavericks and misfits, but even so the back-and-forth proved stimulating. I cornered Stone to ask him about Huautla and Chevé. As he rhapsodized about the unknown realms he still hoped to discover, I basked in the full force of the man’s intense volition. It was easy to see how his 1994 teammates had been first cowed, then alienated, by Stone’s unswerving pursuit of the Holy Grail of world caving. But I caught myself as I realized, This is the kind of brilliant zealot that Columbus must have seemed to his shipmates, or Shackleton to his comrades—a man to be feared but followed.

  The stupendous drama of Stone and am Ende’s six-day push of Huautla into uncharted terrain forms the narrative centerpiece of their book, Beyond the Deep. By the end of the 1994 expedition, using the rebreather, they had solved seven further sumps and all kinds of convoluted slots and tunnels. They had extended Huautla to a relief of 4,839 feet, certifying it as the third-deepest in the world. Still the record holder, the Gouffre Jean-Bernard plunges only 287 feet deeper. At their farthest penetration, Stone and am Ende reached the edge of yet another subterranean pit filled with water. It looked like a tougher challenge than the San Agustin pool. They named it the Mother of All Sumps.

  During the years that Stone’s teams were pushing Chevé and Huautla hard, and French cavers were exploring the farthest nooks of the Vercors and Haute Provence, another band of devotees was quietly investigating a plateau far from France, even farther from Mexico. The Arabika Massif is a limestone sub-range of the Caucasus Mountains, located in the former Soviet republic of Georgia, close to the northeastern shore of the Black Sea. The presence of caves across the massif was known as early as the first decades of the twentieth century, but the consensus of the experts was that the region lacked the potential for really deep pits.

  One of the Arabika caves, named Krubera after Alexander Kruber, an early scientist intrigued by the geology of the region, seemed even less promising than its neighbors. For twenty years after cavers tried to push it in 1963, Krubera yielded a depth of only 290 feet, where a squeeze too tigh
t for human passage seemed to write a finis to the system. The more zealous explorers turned elsewhere—in particular to a cave called Kalsi, which they plumbed to a depth of 3,328 feet, making it not only the first cave in the Soviet Union to exceed 1,000 meters but also the deepest cave yet discovered in that sprawling federation of republics.

  So matters stood until one man, Alexander Klimchouk, had second thoughts. A geologist by profession, Klimchouk put dye into the entrance streams of several Arabika caves. When the luminous water later sprang from hillsides almost at the level of the Black Sea, Krubera gained a new cachet. James Tabor structures the narrative of his enthralling book Blind Descent around the characters and passions of the two leaders of their disparate campaigns, Bill Stone and Alexander Klimchouk. The Ukrainian geologist differs strikingly from his American rival not only in physical presence (five foot eight, with an unprepossessing build) but in temperament. “Stone is a classic Type A—,” writes Tabor, “brusque, impatient, rushing. Klimchouk, or ‘Father Klim,’ as younger cavers sometimes call him, is mild-mannered, soft-spoken, polite to the point of courtliness, deliberate in thought and motion.”

  The contrast between Krubera and Huautla, as well, could not be more dramatic. Krubera lies at a latitude of 43˚ N, fully 1,800 miles north of the Huautla Plateau. As a result, it is a cold cave, in which water immersion poses the immediate threat of hypothermia. Krubera is also relentlessly vertical, while both Chevé and Huautla stand out for the branching complexity of their gently inclined passages. In Tabor’s words, Krubera unfolds as “pitch after pitch connected by short passages called ‘meanders.’ While non-cavers would be terrorized by the yawning pits, one of which is 500 feet deep, experienced explorers look forward to their thrilling rappels, if not to their grinding ascents. They uniformly despise, however, ‘the fucking meanders,’ as they are most frequently called.”