1 00:00:18,018 --> 00:00:20,953 It all begins with water and rock. 2 00:00:22,288 --> 00:00:24,813 As water seeks its level, it becomes acidic. 3 00:00:25,225 --> 00:00:29,525 And when it flows over limestone, it etches a path into the rock. 4 00:00:32,565 --> 00:00:35,864 Given eons of time, water will burrow and carve, 5 00:00:36,102 --> 00:00:41,130 with incredible force, the veins and arteries of planet Earth 6 00:00:47,347 --> 00:00:49,611 So the underworld of caves is born. 7 00:00:51,051 --> 00:00:53,042 And after torrents have done their work, 8 00:00:53,520 --> 00:00:57,718 patient drops do more wonders in a million years or so. 9 00:01:02,595 --> 00:01:06,998 Look now on a landscape no one dreamed existed just a few years ago. 10 00:01:08,301 --> 00:01:12,237 Here are bizarre and fantastic treasures that stun the eye 11 00:01:12,605 --> 00:01:14,163 and strain the imagination. 12 00:01:25,919 --> 00:01:27,978 Here is discovery and danger. 13 00:01:28,988 --> 00:01:30,455 Here is adventure. 14 00:01:49,709 --> 00:01:54,146 In New Mexico, members of a National Geographic Society expedition 15 00:01:54,380 --> 00:01:58,544 explore the world's newest and most exotic major cave. 16 00:01:59,619 --> 00:02:03,180 They are following one of man's most ancient imperatives 17 00:02:03,423 --> 00:02:07,052 to see and understand the unknown. 18 00:02:16,069 --> 00:02:17,627 Join us now as we embark on 19 00:02:17,871 --> 00:02:20,635 an extraordinary journey deep into the earth 20 00:02:20,874 --> 00:02:24,674 to confront MYSTERIES UNDERGROUND. 21 00:03:12,392 --> 00:03:15,452 In the Guadalupe Mountains of southern New Mexico, 22 00:03:15,695 --> 00:03:18,960 an awesome giant has lain hidden for a million years. 23 00:03:20,833 --> 00:03:22,960 Sometimes, in the desert silence, 24 00:03:23,636 --> 00:03:25,604 the monster could be heard breathing. 25 00:03:27,473 --> 00:03:30,271 The sound came from a yawning chasm in the rocks. 26 00:03:32,011 --> 00:03:37,347 In 1986 a trio of weekend explorers broke through a layer of rubble 27 00:03:37,850 --> 00:03:40,341 and discovered a new cave only a few miles 28 00:03:40,587 --> 00:03:42,851 from famous Carlsbad Cavern. 29 00:03:48,828 --> 00:03:52,889 Although the cave entrance lay inside Carlsbad Caverns National Park, 30 00:03:53,533 --> 00:03:57,299 park officials allowed qualified cavers to explore it. 31 00:04:09,983 --> 00:04:13,544 One of them was Rick Bridges, an oil and gas prospector. 32 00:04:18,691 --> 00:04:21,854 Now Bridges leads a hand-picked team of experts, 33 00:04:22,095 --> 00:04:27,158 like rock climber Dave Jones, on the 25th expedition to Lechuguilla. 34 00:04:28,268 --> 00:04:29,530 You got the survey gear, Anne? 35 00:04:31,838 --> 00:04:33,965 Research geologist kiym Cunningham 36 00:04:34,207 --> 00:04:37,643 will handle the science studies for the expedition. 37 00:04:38,177 --> 00:04:41,476 Nuclear test engineer Anne Strait is an expert 38 00:04:41,714 --> 00:04:43,545 in surveying and mapping caves. 39 00:04:45,318 --> 00:04:48,219 And specialist cameraman from England, Sid Perou, 40 00:04:48,454 --> 00:04:52,390 will be the first to document Lechuguilla on motion picture film. 41 00:04:58,631 --> 00:05:01,657 The journey begins with a deceptively ordinary hike. 42 00:05:02,802 --> 00:05:06,898 The cave is named after a desert plant that grows in this harsh, 43 00:05:07,140 --> 00:05:11,634 dry environment-Lechuguilla-Spanish for little lettuce. 44 00:05:16,649 --> 00:05:18,674 Forty people will support the venture, 45 00:05:18,918 --> 00:05:21,853 including two support teams to pack in supplies 46 00:05:22,088 --> 00:05:24,249 and batteries for photographic lights. 47 00:05:26,659 --> 00:05:27,751 On high rope. 48 00:05:28,728 --> 00:05:30,218 We tend to have this feeling that 49 00:05:30,463 --> 00:05:33,955 the surface of the earth is the life of the earth. 50 00:05:34,200 --> 00:05:35,360 But we're just this small, 51 00:05:35,601 --> 00:05:38,069 thin little shell that we choose to call our world, 52 00:05:38,504 --> 00:05:43,339 and beneath it there's an entire realm that we know very little about. 53 00:05:43,976 --> 00:05:45,170 And we can, if we choose, 54 00:05:45,411 --> 00:05:48,847 enter that realm and we can learn something from it. 55 00:05:50,183 --> 00:05:51,411 I will never go to the moon, 56 00:05:51,651 --> 00:05:54,745 but I can go to a cave the nobody else has been to 57 00:05:55,054 --> 00:05:57,887 and have the same elation of exploration in the sense 58 00:05:58,591 --> 00:06:01,719 that I have gone where no one's gone before. 59 00:06:02,628 --> 00:06:03,595 Bombs away. 60 00:06:03,830 --> 00:06:06,663 I would like to think that had I lived in another time 61 00:06:06,899 --> 00:06:07,957 I would have been an explorer. 62 00:06:08,201 --> 00:06:10,965 You know, had I lived in the late 1700s, 63 00:06:11,204 --> 00:06:13,570 I would have wanted to know what was across the Appalachian Mountains. 64 00:06:13,806 --> 00:06:16,206 If I'd been around when Lewis and Clark went to the coast, 65 00:06:16,442 --> 00:06:18,239 I'd liked to have gone with them, you know. 66 00:06:18,478 --> 00:06:20,412 And I think most people that cave 67 00:06:20,646 --> 00:06:24,673 at this level and do this kind of exploration feel that way. 68 00:06:26,285 --> 00:06:28,310 Here, Bridges and his companions 69 00:06:28,554 --> 00:06:31,421 excavated to break into Lechuguilla for the first time. 70 00:06:34,761 --> 00:06:37,559 Now the entrance is protected by a lockable hatchway. 71 00:06:40,733 --> 00:06:43,759 Through this tiny aperture the cave breathes 72 00:06:44,704 --> 00:06:46,262 blowing air out or sucking 73 00:06:46,506 --> 00:06:50,306 it in to equalize with the barometric pressure above ground. 74 00:06:51,978 --> 00:06:55,175 Winds up to 60 miles an hour howl out of here, 75 00:06:55,615 --> 00:06:58,175 hinting at the vast underworld below. 76 00:07:02,522 --> 00:07:05,320 Today, this is Lechuguilla's only known entrance, 77 00:07:06,092 --> 00:07:07,684 and there may have never been another. 78 00:07:08,594 --> 00:07:11,620 For a million years this place has lain undisturbed. 79 00:07:12,732 --> 00:07:15,565 In a real sense, it is a primordial world, 80 00:07:16,035 --> 00:07:19,232 untouched by all but microscopic forms of life. 81 00:07:23,743 --> 00:07:24,732 On rope! 82 00:07:27,914 --> 00:07:29,506 It's a long ways down. 83 00:07:30,983 --> 00:07:32,450 See you guys on the bottom. 84 00:07:33,753 --> 00:07:35,084 Dave Jones starts down 85 00:07:35,321 --> 00:07:38,779 the 150 foot pit called Boulder Falls 86 00:07:39,792 --> 00:07:42,352 It was here that the first explorers realized 87 00:07:43,029 --> 00:07:45,293 what a vast place they had discovered. 88 00:07:46,499 --> 00:07:47,830 As you progress down, 89 00:07:48,067 --> 00:07:50,365 it gets steeper and steeper and pretty soon you're free hanging, 90 00:07:50,603 --> 00:07:52,332 but your feet are still against the rock 91 00:07:53,206 --> 00:07:56,266 And all of a sudden you rappel 92 00:07:56,509 --> 00:07:57,874 by this little ledge 93 00:07:58,177 --> 00:08:03,137 and there's no more rock. There's nothing in any direction. 94 00:08:23,569 --> 00:08:24,968 Beyond the base of the pit 95 00:08:25,204 --> 00:08:27,866 the cave branches off in all directions. 96 00:08:29,542 --> 00:08:33,376 Only computer imagery can portray this labyrinth. 97 00:08:39,418 --> 00:08:42,319 After the May 1986 exploration 98 00:08:42,555 --> 00:08:45,217 the cave was known to be 700 feet deep 99 00:08:45,458 --> 00:08:47,323 and more than half a mile long. 100 00:08:49,095 --> 00:08:55,523 Today the system totals 60 miles and plummets more than 1,600 feet. 101 00:08:56,769 --> 00:09:01,536 Twisting capillaries and veins pierce the earth in all directions. 102 00:09:03,876 --> 00:09:07,073 This is a gigantic maze in three dimensions, 103 00:09:07,847 --> 00:09:11,874 defying conventional ideas of direction and scale. 104 00:09:16,689 --> 00:09:20,147 Footprints remain forever in this fragile environment. 105 00:09:21,027 --> 00:09:24,053 Plastic ribbons keep cavers on main trails. 106 00:09:26,732 --> 00:09:31,032 Expeditions into Lechuguilla have been likened to exploring Everest 107 00:09:31,370 --> 00:09:32,462 only in reverse. 108 00:09:35,608 --> 00:09:39,738 The team is headed for Base Camp still hours away. 109 00:09:49,722 --> 00:09:52,816 The trail leads on into inky blackness 110 00:09:53,726 --> 00:09:56,490 Often they traverse chambers so vast 111 00:09:56,729 --> 00:09:59,289 the cave walls are barely discernible. 112 00:10:04,503 --> 00:10:06,835 Gypsum crystals sparkle along the route. 113 00:10:08,374 --> 00:10:12,276 Now, cavers encounter Lechuguilla's fantastic decorations 114 00:10:12,678 --> 00:10:13,667 for the first time. 115 00:10:17,049 --> 00:10:20,507 Helictites and gypsum flowers extrude from the walls 116 00:10:21,420 --> 00:10:24,548 fragile gardens that have taken centuries to blossom, 117 00:10:25,291 --> 00:10:29,387 as minerals have been squeezed from the rocks like toothpaste from a tube. 118 00:10:33,466 --> 00:10:35,434 Beauty abounds. 119 00:10:35,735 --> 00:10:37,828 These jewels of the underground 120 00:10:38,070 --> 00:10:40,630 are exquisitely delicate needles of selenite. 121 00:10:59,458 --> 00:11:01,824 With the constant maneuvering up down 122 00:11:02,061 --> 00:11:04,461 and through the cave's difficult terrain, 123 00:11:04,697 --> 00:11:08,133 50 pound backpacks become painful burdens. 124 00:11:18,778 --> 00:11:22,475 Always, in Lechuguills, danger is not far away. 125 00:11:26,085 --> 00:11:29,816 Okay, on three. One, two, three. 126 00:11:30,656 --> 00:11:35,559 In 1991 seasoned caver Emily Mobley slipped and broke her leg 127 00:11:35,795 --> 00:11:39,287 while working on a surveying expedition in the cave's western sector. 128 00:11:40,399 --> 00:11:42,663 A mile and a half from the entrance, 129 00:11:42,902 --> 00:11:44,870 900 feet below the surface, 130 00:11:45,371 --> 00:11:49,831 this accident would trigger the largest and most publicized cave rescue 131 00:11:50,076 --> 00:11:51,668 in U.S. History. 132 00:12:03,923 --> 00:12:05,550 A hundred experienced cavers 133 00:12:05,791 --> 00:12:09,420 summoned to the scene would labor four arduous days 134 00:12:09,662 --> 00:12:10,856 to bring her to safety. 135 00:12:27,947 --> 00:12:30,211 The bond of comradeship that unites 136 00:12:30,449 --> 00:12:34,681 the caving community was seldommore evident than during this emergency. 137 00:12:35,454 --> 00:12:40,448 Every caver knows and instinctively responds to the code of the underground 138 00:12:40,993 --> 00:12:45,020 that only cavers can save and protect each other. 139 00:12:54,507 --> 00:12:59,001 After almost four hours, the expedition reaches Lake Lebarge, 140 00:12:59,245 --> 00:13:03,011 the first sizeable body of water to be discovered inthis branch of Lechuguilla. 141 00:13:06,619 --> 00:13:07,142 Beautiful! 142 00:13:07,386 --> 00:13:09,149 One of the greatest sights in caving, isn't it? 143 00:13:09,388 --> 00:13:11,219 Yes. Fantastic. Is this Lake Lebarge? 144 00:13:11,457 --> 00:13:14,824 Yeah. Lebarge Borehole looks easier now. 145 00:13:15,060 --> 00:13:16,186 Beautiful! 146 00:13:16,529 --> 00:13:17,427 On rope! 147 00:13:28,307 --> 00:13:30,867 The lake completely blocks the way ahead. 148 00:13:31,310 --> 00:13:34,211 Cavers had to wade it until they found a detour 149 00:13:35,381 --> 00:13:36,973 tricky, but possible. 150 00:13:39,185 --> 00:13:42,177 Well, I think of particular moves like dancing around the edge of Lebarge 151 00:13:42,721 --> 00:13:45,019 as almost a ballet, an underground ballet. 152 00:13:45,257 --> 00:13:47,885 I know where my footholds are; I know where my handholds are. 153 00:13:48,127 --> 00:13:51,153 I know if I hit them just right and move just right 154 00:13:51,397 --> 00:13:53,991 some of them are kind of dynamic in so much as you leave one handhold 155 00:13:54,233 --> 00:13:55,791 while you're going for the next foothold. 156 00:13:56,035 --> 00:13:58,265 And if you do that just right and you have your pack balanced 157 00:13:58,504 --> 00:14:00,938 just right, you flow through it real smoothly. 158 00:14:01,173 --> 00:14:03,300 And so I think it's very much like doing a dance, 159 00:14:03,542 --> 00:14:04,702 a very intricate dance. 160 00:14:04,977 --> 00:14:06,467 And you want to do it perfectly, 161 00:14:06,712 --> 00:14:08,805 you know, and it's very beautiful when you do. 162 00:14:12,151 --> 00:14:13,049 Deeper into the cave, 163 00:14:13,285 --> 00:14:16,982 mineral formations become more fantastic and delicate. 164 00:14:19,892 --> 00:14:22,656 Cavers must move among them with great care. 165 00:14:25,564 --> 00:14:27,498 Spikes of aragonite, 166 00:14:27,733 --> 00:14:31,726 one form of calcium carbonate, grow in fragile bushes. 167 00:14:32,071 --> 00:14:34,801 The gentlest touch could damage them. 168 00:14:40,312 --> 00:14:42,507 There is infinite contrast here. 169 00:14:42,748 --> 00:14:47,776 The now famous Chandelier Ballroom is one of caving's classic beauty spots 170 00:14:48,888 --> 00:14:51,880 Plumes of gypsum sprout from the ceiling, 171 00:14:52,358 --> 00:14:54,019 some as long as 20 feet 172 00:14:54,860 --> 00:14:58,819 the most dazzing examples of their type ever found. 173 00:15:22,388 --> 00:15:24,879 Utter silence pervades Lechuguilla. 174 00:15:25,224 --> 00:15:27,715 The only sound is made by the intruder 175 00:15:37,503 --> 00:15:41,234 In the constant 68-degree temperature and high humidity, 176 00:15:41,473 --> 00:15:43,839 dehydration is always a threat. 177 00:15:46,211 --> 00:15:47,508 Anybody else need any hot water? 178 00:15:47,846 --> 00:15:49,370 For some, the notion of life 179 00:15:49,615 --> 00:15:52,243 with almost a quarter mile of rock overhead 180 00:15:52,484 --> 00:15:55,078 can be oppressive, even terrifying. 181 00:15:55,554 --> 00:15:58,887 But cavers like Bridges relish the experience. 182 00:15:59,191 --> 00:16:03,321 It's almost like coming back to home after you've been gone for a while. 183 00:16:03,629 --> 00:16:08,464 It's a very comfortable feeling to me, particularly in that particular cave. 184 00:16:08,867 --> 00:16:13,031 And you know it's a sense of isolation 185 00:16:13,272 --> 00:16:15,365 The world becomes very simple 186 00:16:19,278 --> 00:16:22,406 Here there is no day or night. 187 00:16:22,648 --> 00:16:25,674 If they ignore the time, cavers tend to stay awake, 188 00:16:25,918 --> 00:16:29,012 and sleep, for longer and longer periods. 189 00:16:33,959 --> 00:16:35,051 In Lechuguilla Cave, 190 00:16:35,294 --> 00:16:37,057 there is little evidence of life. 191 00:16:37,963 --> 00:16:39,988 But this is rare. 192 00:16:44,837 --> 00:16:49,274 Many caves harbor a hidden kingdom of creatures, dominated by bats. 193 00:16:51,910 --> 00:16:53,639 Bats thrive in darkness. 194 00:16:53,979 --> 00:16:55,606 They navigate not by sight, 195 00:16:55,848 --> 00:16:58,817 but by subtle patterns of reflected sound. 196 00:17:00,452 --> 00:17:03,114 Some caves are home to millions of bats, 197 00:17:03,389 --> 00:17:06,187 the greatest concentration of mammals anywhere. 198 00:17:08,260 --> 00:17:10,956 Their nitrogen-rich droppings, or guano, 199 00:17:11,196 --> 00:17:13,562 are harvested as a fertilizer. 200 00:17:13,932 --> 00:17:18,232 Large deposits produce a toxic gas, which can be lethal. 201 00:17:26,045 --> 00:17:30,209 Mountains of bat guano support the intricate food chain underground. 202 00:17:31,950 --> 00:17:35,147 Sometimes, an injured bat, or a baby, 203 00:17:35,387 --> 00:17:39,323 falls into the guano and itself becomes food. 204 00:17:41,794 --> 00:17:44,854 Within minutes the bat is reduced to a skeleton. 205 00:17:51,203 --> 00:17:54,036 Abundant underground, the cave cricket 206 00:17:55,541 --> 00:17:59,500 Crickets spend much of their time gathering food outside their caves, 207 00:17:59,745 --> 00:18:03,442 but inside they perform a vital role as scavengers. 208 00:18:08,754 --> 00:18:13,555 In mute testament to their environment fish have evolved here without eyes. 209 00:18:16,995 --> 00:18:19,555 The salamander has dispensed with eyes, too, 210 00:18:20,199 --> 00:18:24,135 and has no need of skin pigment in a world without sunlight. 211 00:18:30,109 --> 00:18:33,704 People have probably always found shelter in aves. 212 00:18:34,046 --> 00:18:35,638 Thousands of years ago, 213 00:18:35,881 --> 00:18:39,681 as much of the world still lay in the grip of the last Ice Age, 214 00:18:39,918 --> 00:18:43,786 prehistoric hunters left spectacular evidence behind them. 215 00:18:48,827 --> 00:18:52,194 The human spirit was born and nurtured here, 216 00:18:53,065 --> 00:18:56,034 its expression etched on walls of stone. 217 00:19:01,140 --> 00:19:05,008 By the early 20th century most people lived elsewhere. 218 00:19:05,244 --> 00:19:10,147 But science and curiosity drove some to explore deeper underground. 219 00:19:11,049 --> 00:19:15,679 Magnesium flares lit the way, filling dark voids with light. 220 00:19:18,824 --> 00:19:22,555 Geologists squeezed into subterranean chambers 221 00:19:22,794 --> 00:19:25,695 seeking to understand their origin and structure. 222 00:19:31,637 --> 00:19:35,095 And soon the ancient lure of caves turned to profit. 223 00:19:35,707 --> 00:19:37,834 Tourists went underground. 224 00:19:41,580 --> 00:19:42,376 Then and now, 225 00:19:42,614 --> 00:19:45,674 humans have been compelled to seek out caves, 226 00:19:45,951 --> 00:19:49,284 and to combat the gloom with gay defiance. 227 00:19:55,093 --> 00:19:58,688 In the United States, New Mexico's Carlsbad Caverns 228 00:19:58,931 --> 00:20:01,900 was declared a national park in 1930. 229 00:20:02,367 --> 00:20:04,835 But natural wonders were not enough. 230 00:20:05,070 --> 00:20:08,972 Carlsbad and other caves promoted all sorts of attractions, 231 00:20:09,208 --> 00:20:11,233 some a bit farfetched. 232 00:20:11,977 --> 00:20:14,605 The time will come when some master musician 233 00:20:14,947 --> 00:20:20,249 in the Carlsbad Cavern will be able to create s symphony in stone 234 00:20:43,475 --> 00:20:46,239 Many parts of the world are known for caves. 235 00:20:46,478 --> 00:20:49,106 Because most lie on limestone bedrock, 236 00:20:49,348 --> 00:20:52,545 the soil is often thin and life is hard 237 00:20:53,752 --> 00:20:56,949 So it has often been in the remote uplands of Kentucky. 238 00:20:58,924 --> 00:21:02,087 But the automobile brought a new source of wealth 239 00:21:02,327 --> 00:21:05,194 city folks, eager for amusement. 240 00:21:06,131 --> 00:21:09,498 Everyone who owned a cave hung up a sign. 241 00:21:09,735 --> 00:21:13,694 Each was touted as being bigger and better than the others. 242 00:21:13,939 --> 00:21:18,399 The so-called Cave Wars spurred bitter feuds and even violence 243 00:21:19,778 --> 00:21:22,906 Crystal Cave belonged to the Collins family, 244 00:21:23,148 --> 00:21:26,640 but it was too far from the beaten path to prosper. 245 00:21:29,488 --> 00:21:33,288 Thirty-seven-year-old Floyd, one of the Collins boys, 246 00:21:33,525 --> 00:21:37,928 was determined to find a cave closer to the highway. 247 00:21:38,163 --> 00:21:42,759 He set off alone on a cold winter morning in January 1925 248 00:21:43,468 --> 00:21:47,234 and squeezed into a narrow, twisting crack in the earth, 249 00:21:47,472 --> 00:21:49,770 never before explored. 250 00:21:53,312 --> 00:21:55,872 A hundred feet or so into the tight passageway 251 00:21:56,114 --> 00:22:01,984 Floyd dislodges a rock that falls on his leg and pains his left foot. 252 00:22:06,792 --> 00:22:11,820 Every detail of this fateful mishap will soon be known throughout the world 253 00:22:14,032 --> 00:22:18,059 Struggling to free himself, Floyed becomes more tightly wedged. 254 00:22:18,570 --> 00:22:20,765 His arms are pinned at his sides. 255 00:22:21,540 --> 00:22:24,100 He can do nothing but shout for help. 256 00:22:25,744 --> 00:22:28,838 Twenty-four hours later Floyd's cries are heard. 257 00:22:29,348 --> 00:22:32,340 A younger brother, Homer, manages to reach him. 258 00:22:33,852 --> 00:22:36,013 Coffee and sandwiches revive Floyd, 259 00:22:36,388 --> 00:22:39,789 but no amount of tugging or pulling will set him free. 260 00:22:42,561 --> 00:22:46,497 Would-be rescuers knock down more dirt and rocks. 261 00:22:48,533 --> 00:22:50,433 Soon more help arrives, 262 00:22:50,669 --> 00:22:54,161 but rescue efforts are clumsy and disorganized. 263 00:22:55,374 --> 00:22:57,968 Curious onlookers begin to gather. 264 00:22:58,210 --> 00:23:00,872 They become restive and quarrelsome. 265 00:23:01,813 --> 00:23:03,440 A week goes by. 266 00:23:03,882 --> 00:23:07,875 Floyd is still alive and the crowed swells to thousand. 267 00:23:09,020 --> 00:23:11,147 It becomes a carnival. 268 00:23:11,390 --> 00:23:15,383 Souvenirs are sold and moonshiners arrive on the scene. 269 00:23:15,994 --> 00:23:20,021 It's hard to maintain order and the National Guard is summoned. 270 00:23:24,536 --> 00:23:27,528 Skeets Miller a 21-year-old newspaper reporter, 271 00:23:27,773 --> 00:23:32,107 braves the tortuous passage seven times to comfort Floyd 272 00:23:32,344 --> 00:23:34,642 and describe his plight. 273 00:23:35,213 --> 00:23:37,477 Miller takes down food and drink 274 00:23:37,716 --> 00:23:40,276 and an electric light bulb to keep Floyd warm. 275 00:23:41,119 --> 00:23:45,283 In bitter cold and rain, little more can be done for him. 276 00:23:47,492 --> 00:23:52,657 When a cave-in blocks the passage, a rescue shaft is begun. 277 00:23:52,898 --> 00:23:57,494 People all over the country join Floyd's family in prayer. 278 00:24:01,907 --> 00:24:04,740 Floyd's brothers expect the worst. 279 00:24:04,976 --> 00:24:08,275 Rescuers finally reach him on the 18th day. 280 00:24:08,780 --> 00:24:10,645 It is too late. 281 00:24:10,949 --> 00:24:13,474 Floyd has been dead for some time. 282 00:24:13,952 --> 00:24:15,681 The crowd goes home. 283 00:24:15,921 --> 00:24:19,152 The public is soon interested in other things. 284 00:24:21,393 --> 00:24:25,090 It takes two months to recover the body. 285 00:24:28,767 --> 00:24:31,634 The rock that trapped Floyd was not a boulder, 286 00:24:31,903 --> 00:24:37,603 but a mere 27-pound stone, shaped like a leg of lamb. 287 00:24:39,377 --> 00:24:42,608 His death left a legacy of fear of the dark, 288 00:24:42,848 --> 00:24:46,841 mysterious underground that haunts many to this day. 289 00:24:54,693 --> 00:24:59,528 Today, there are about 16,000 devotees of caving in the U.S. 290 00:25:00,899 --> 00:25:03,959 Here, where Tennessee, Alabama, and Georgia meet, 291 00:25:04,302 --> 00:25:06,964 the countryside is studded by deep pits 292 00:25:07,205 --> 00:25:11,266 vertical caves the delight of weekend enthusiasts. 293 00:25:15,747 --> 00:25:17,078 Nine-year-old Leah Brown 294 00:25:17,315 --> 00:25:20,284 holds a world speed record for rope climbing. 295 00:25:21,853 --> 00:25:24,083 Her partner, Avis Van Swearingen, 296 00:25:24,322 --> 00:25:29,123 also holds a climbing record for women over the age of 60. 297 00:25:31,730 --> 00:25:33,288 With skill and courage 298 00:25:33,532 --> 00:25:36,763 they suspend their lives on a slender thread. 299 00:25:38,470 --> 00:25:40,165 We call that rope the nylon highway 300 00:25:40,405 --> 00:25:42,635 because it takes us to wonderful places 301 00:25:42,874 --> 00:25:48,210 and new parts of the cave, and it's the only way you can get there 302 00:25:52,651 --> 00:25:55,882 If I'm the first one down a drop, and I have been the first, 303 00:25:56,121 --> 00:25:58,612 the very first person to ever go down a drop... 304 00:25:59,324 --> 00:26:02,816 if we can't really tell if the rope reaches the bottom, 305 00:26:03,061 --> 00:26:06,861 the person who goes down first wears their climbing gear, too, 306 00:26:07,198 --> 00:26:10,292 so that you can put your climbing gear on the rope and come up. 307 00:26:10,869 --> 00:26:13,633 Also, we put a knot at the bottom of that rope 308 00:26:13,872 --> 00:26:16,397 so we can't rappel off the end of it, 309 00:26:16,675 --> 00:26:18,666 which has happened to people. 310 00:26:21,680 --> 00:26:23,011 I like the deep pits, 311 00:26:23,248 --> 00:26:26,979 because when they're deep, you get to go fast more. 312 00:26:27,218 --> 00:26:29,379 That's why I like the deep pits, 313 00:26:29,821 --> 00:26:33,951 because the short ones you don't get to go fast very long. 314 00:26:35,894 --> 00:26:38,488 The first time I did it in a pit, 315 00:26:38,730 --> 00:26:43,099 it was only a 90-foot pit and I didn't get scared. 316 00:26:43,335 --> 00:26:45,633 I don't get scared very easily. 317 00:26:45,870 --> 00:26:47,132 I like going fast. 318 00:26:47,372 --> 00:26:48,999 When I go down fast, 319 00:26:49,240 --> 00:26:53,700 the floor is real tiny and then it starts getting bigger and bigger, 320 00:26:53,945 --> 00:26:55,412 and I like to watch that. 321 00:27:04,022 --> 00:27:06,047 An unfettered commitment to their sport 322 00:27:06,291 --> 00:27:11,058 compels cavers to seek new thrills in undiscovered places. 323 00:27:11,296 --> 00:27:14,697 For some, the quest for adventure knows no boundary. 324 00:27:19,304 --> 00:27:20,828 The Austrian Apls. 325 00:27:21,072 --> 00:27:26,339 A fifth of the world's deepest caves are located here, high in the mountains 326 00:27:28,279 --> 00:27:31,646 These ice caves are 5,000 feet above sea level. 327 00:27:31,983 --> 00:27:37,114 They are natural deep freezes where ice remains, even in hot summers 328 00:28:05,684 --> 00:28:08,847 Here, geological time is condensed. 329 00:28:09,087 --> 00:28:11,180 We can witness the growth of ice formations 330 00:28:11,423 --> 00:28:14,153 in short periods of months or years, 331 00:28:14,759 --> 00:28:18,217 which in their stone counterparts would take centuries. 332 00:28:51,463 --> 00:28:54,091 From year to year these caves are never the same. 333 00:28:54,399 --> 00:28:56,162 As they thaw and freeze again, 334 00:28:56,401 --> 00:28:59,837 the fantastic ice formations are ever changing. 335 00:29:01,506 --> 00:29:05,340 Few places on earth are more beautiful or more treacherous, 336 00:29:06,177 --> 00:29:08,111 with perhaps one exception. 337 00:29:12,183 --> 00:29:16,483 Some cavers have merged their love of the unknown with a passion for diving, 338 00:29:16,788 --> 00:29:22,021 venturing into a bizarre world underground and under water. 339 00:29:27,866 --> 00:29:29,663 Originally formed above sea level, 340 00:29:29,901 --> 00:29:34,201 these caves became submerged about 10,000 years ago 341 00:29:34,439 --> 00:29:36,964 as the last Ice Age retreated. 342 00:29:37,208 --> 00:29:40,439 They are now 70 feet beneath the surface. 343 00:29:56,461 --> 00:30:00,227 Underwater caves are deathtraps for the inexperienced. 344 00:30:20,151 --> 00:30:21,083 But, from time to time, 345 00:30:21,319 --> 00:30:25,050 tempting fate can have astounding rewards. 346 00:30:28,326 --> 00:30:31,489 In 1990, when exploring a submerged tunnel off 347 00:30:31,729 --> 00:30:33,720 the Mediterranean coast of France, 348 00:30:33,965 --> 00:30:37,492 a professional diver surfaced in a hidden chamber. 349 00:30:39,437 --> 00:30:44,636 He found a treasure chest of art, perhaps 18,000 years old. 350 00:30:45,944 --> 00:30:50,176 Paintings and engravings depict animals that roamed southern Europe 351 00:30:50,448 --> 00:30:52,746 before the last great ice sheets melted 352 00:30:54,485 --> 00:30:57,943 Some experts question the authenticity of the art, 353 00:30:58,189 --> 00:31:00,657 but close examination is impossible. 354 00:31:04,062 --> 00:31:07,554 Cosquer Cave is a place of haunting mystery. 355 00:31:08,433 --> 00:31:12,631 To protect it, the cave is now sealed by order of the French government. 356 00:31:13,204 --> 00:31:17,573 In time a new entrance may be built and the truth known. 357 00:31:24,616 --> 00:31:28,017 An expanse of sinkholes and depressions pockmark 358 00:31:28,253 --> 00:31:29,845 south central Kentucky 359 00:31:30,088 --> 00:31:33,990 where, beneath the surface, the limestone is riddled with caves. 360 00:31:35,393 --> 00:31:39,159 They are everywhere, an integral part of the landscape. 361 00:31:40,698 --> 00:31:42,529 This is Floyd Collins country, 362 00:31:42,767 --> 00:31:47,204 and the contest to attract the tourist dollar still rages on. 363 00:31:49,407 --> 00:31:53,468 The star attraction is Mammoth the world's longest cave. 364 00:31:55,346 --> 00:31:57,871 A national park since 1941, 365 00:31:58,116 --> 00:32:01,643 the cave now draws more than half a million visitors a year. 366 00:32:07,292 --> 00:32:08,156 Back in the 1800s 367 00:32:08,393 --> 00:32:11,521 tour guides here were often black slaves. 368 00:32:12,063 --> 00:32:14,293 One of them, Stephen Bishop, 369 00:32:14,632 --> 00:32:17,499 became perhaps the greatest caver of them all. 370 00:32:18,436 --> 00:32:20,904 On his own, with little more than a lamp, 371 00:32:21,205 --> 00:32:22,968 a rope, and a sketchbook, 372 00:32:23,574 --> 00:32:26,975 Bishop explores the depths of Mammoth Cave. 373 00:32:28,346 --> 00:32:33,648 He creates a surprisingly accurate map of this complex underground maze. 374 00:32:35,553 --> 00:32:36,451 Deep in the cave 375 00:32:36,888 --> 00:32:39,584 Bishop is confronted by a gaping void 376 00:32:39,824 --> 00:32:42,725 that came to be known as Bottomless Pit. 377 00:32:58,142 --> 00:33:03,170 Beyond, Bishop explores regions that had never been visited in his time 378 00:33:03,648 --> 00:33:06,811 But in these remote reaches he hinds evidence 379 00:33:07,051 --> 00:33:09,178 that someone has preceded him. 380 00:33:22,934 --> 00:33:25,664 Some archaeologists believe that Stephen Bishop 381 00:33:26,204 --> 00:33:30,937 may have also encountered one of Mammoth's most compelling mysteries 382 00:33:31,909 --> 00:33:33,501 Trapped under a boulder 383 00:33:33,745 --> 00:33:37,010 are the ancient remains of a human being. 384 00:33:39,951 --> 00:33:43,751 Not for another century would the mummified body be rediscovered 385 00:33:43,988 --> 00:33:46,855 and then as the technology became available, 386 00:33:47,091 --> 00:33:50,254 removed from beneath the six-ton boulder. 387 00:33:50,495 --> 00:33:51,985 A sensation in its time, 388 00:33:52,230 --> 00:33:55,791 the mysterious body would be on public display for years 389 00:33:56,034 --> 00:33:59,094 and given the name Lost John. 390 00:34:00,505 --> 00:34:02,700 Two to three thousand years ago 391 00:34:02,940 --> 00:34:06,273 this man was digging around the base of a heavy rock 392 00:34:06,511 --> 00:34:08,570 when it dislodged and crushed him. 393 00:34:11,549 --> 00:34:13,107 What was he doing here? 394 00:34:13,351 --> 00:34:15,182 How did he get here? 395 00:34:15,420 --> 00:34:19,254 No one believed that ancient humans could have ventured this far 396 00:34:19,490 --> 00:34:21,856 into the forbidding depths of Mammoth Cave. 397 00:34:25,830 --> 00:34:29,027 Today, new evidence helps to answer these questions. 398 00:34:29,367 --> 00:34:32,461 Archaeologist Ken Tankersley has spent years 399 00:34:32,703 --> 00:34:36,833 investigating the traces of ancient humans in Mammoth. 400 00:34:37,842 --> 00:34:40,834 Armed with cane reeds collected near the park, 401 00:34:41,079 --> 00:34:44,242 Tankersley simulates the methods prehistoric 402 00:34:44,482 --> 00:34:46,473 explorers would have used here. 403 00:34:52,990 --> 00:34:57,051 We have long known that human beings lived near the entrance of caves. 404 00:34:57,295 --> 00:35:00,059 But Lost John suggested that prehistoric people 405 00:35:00,298 --> 00:35:02,289 had gone far into Mammoth 406 00:35:02,533 --> 00:35:04,763 perhaps two day's travel. 407 00:35:06,637 --> 00:35:08,195 Was this possible? 408 00:35:08,673 --> 00:35:10,937 At first Tankersley himself had doubts 409 00:35:13,177 --> 00:35:16,510 I'm always amazed when I think about 410 00:35:16,747 --> 00:35:19,272 what it takes for us to go into a cave. 411 00:35:19,517 --> 00:35:22,543 We wear a hard hat; we wear out caving lamp, 412 00:35:22,787 --> 00:35:24,118 whether it's electric or carbide; 413 00:35:24,355 --> 00:35:26,414 and we carry two sources of back-up light. 414 00:35:26,691 --> 00:35:30,127 We wear enough clothing to ward off hypothermia. 415 00:35:30,761 --> 00:35:33,992 These people wore virtually nothing 416 00:35:34,565 --> 00:35:36,590 loin cloths at best. 417 00:35:36,834 --> 00:35:38,131 Probably most frequently, 418 00:35:38,369 --> 00:35:42,328 based on what we've seen in the cave in terms of human remains, 419 00:35:42,940 --> 00:35:47,104 these people were naked, carrying nothing but cane reed torches 420 00:35:54,185 --> 00:35:58,178 The reed torches were the only light source available to ancient humans. 421 00:35:58,723 --> 00:36:02,022 They produce surprisingly efficient illumination 422 00:36:02,527 --> 00:36:05,587 and conjure ghosts from the heavy shadows. 423 00:36:15,206 --> 00:36:17,470 Their daring was incredible. 424 00:36:17,708 --> 00:36:21,166 For humans, light is life in a cave. 425 00:36:21,412 --> 00:36:24,142 But these explorers traveled up to 12 miles 426 00:36:24,382 --> 00:36:28,716 with nothing but reed torches between them and a horrible fate. 427 00:36:30,521 --> 00:36:33,354 Their pathway can be followed even now 428 00:36:39,530 --> 00:36:43,626 A trail of burned torch fragments leads Tankersley and his companions 429 00:36:43,868 --> 00:36:47,065 to a cavity in the rock face. 430 00:36:48,439 --> 00:36:50,873 Digging marks and a crude implement 431 00:36:51,108 --> 00:36:53,474 are evidence of some kind of activity here. 432 00:36:54,679 --> 00:36:58,046 That's magnificent. Notice the cut edge. 433 00:36:59,450 --> 00:37:01,475 A primitive tool, 434 00:37:01,719 --> 00:37:04,688 one of dozens found deep in the cave. 435 00:37:04,989 --> 00:37:07,048 What was it used for? 436 00:37:07,825 --> 00:37:09,292 Another clue: 437 00:37:09,527 --> 00:37:14,590 A rich seam of selenite crystal courses through the rock face nearby. 438 00:37:16,667 --> 00:37:19,761 These findings prove that prehistoric people were engaged 439 00:37:20,004 --> 00:37:23,770 in widespread mining of crystals throughout the cave. 440 00:37:27,011 --> 00:37:29,605 The scale of the operation was staggering. 441 00:37:29,947 --> 00:37:32,711 Tons of material were removed. 442 00:37:33,050 --> 00:37:37,214 The mining continued without interruption for over a thousand years 443 00:37:38,322 --> 00:37:42,691 The ancient miners took selenite and other minerals from the cave. 444 00:37:43,361 --> 00:37:46,296 But what they were used for remains a mystery 445 00:37:46,664 --> 00:37:49,132 as medicines, or ornaments, 446 00:37:50,067 --> 00:37:53,969 or for use in rituals? Perhaps all three. 447 00:37:55,673 --> 00:37:59,370 Just as mysteriously, around the time of the birth of Christ 448 00:37:59,610 --> 00:38:01,510 the mining suddenly ceased. 449 00:38:02,046 --> 00:38:04,708 As yet no one knows why. 450 00:38:05,616 --> 00:38:09,780 All that remains is abundant evidence that they once were here, 451 00:38:10,087 --> 00:38:14,148 driven by needs and desires we may never understand. 452 00:38:15,092 --> 00:38:18,493 To our right, down below, is the famous Bottomless Pit. 453 00:38:19,397 --> 00:38:23,959 For many, many years lights were not sufficient to reach the bottom. 454 00:38:24,368 --> 00:38:28,099 Visiting Mammoth today is a journey through time. 455 00:38:28,906 --> 00:38:32,171 But as they are guided along comfortable tourist trails, 456 00:38:32,410 --> 00:38:37,006 few visitors can imagine the tortuous passageways that lie beyond them. 457 00:38:37,348 --> 00:38:41,808 Not knowing the true depth of the pit or what lay on the other side. 458 00:38:43,220 --> 00:38:45,211 Reaching the other side, 459 00:38:45,456 --> 00:38:51,190 they were surprised to find an avenue over there and more cave. 460 00:38:51,429 --> 00:38:54,489 This opened up the doorway to the vast 461 00:38:54,732 --> 00:38:57,633 unknown mileage that we all Mammoth Cave. 462 00:38:59,570 --> 00:39:03,734 Mammoth Cave Ridge skirts the Houchins Valley. 463 00:39:05,443 --> 00:39:08,037 On the other side, beneath Flint Ridge 464 00:39:08,279 --> 00:39:12,443 lies another cave network, once shrouded in mystery. 465 00:39:15,119 --> 00:39:17,178 Here, 40 years ago, 466 00:39:17,421 --> 00:39:21,289 one of the great exploits of cave exploration began. 467 00:39:23,561 --> 00:39:28,396 In the 1950s a group of weekend adventurers began an intensive probe 468 00:39:28,632 --> 00:39:30,862 into the secrets of Flint Ridge. 469 00:39:31,102 --> 00:39:34,162 There had long been talk of a vast underground system 470 00:39:34,405 --> 00:39:36,896 that might link all the caves in the area. 471 00:39:40,177 --> 00:39:45,774 It began as an exciting pastime. It became a grueling obsession. 472 00:39:46,784 --> 00:39:50,185 Over the years hundreds of men and women took part. 473 00:39:50,454 --> 00:39:53,890 There were untold yards of muddy crawlways. 474 00:39:54,125 --> 00:39:59,620 There were pits and crevices and mazes from which there seemed no escape. 475 00:40:01,265 --> 00:40:05,861 Flint ridge developed its own colorful place names: The Corkscrew, 476 00:40:06,203 --> 00:40:10,663 Shower Shaft, Agony Avenue. 477 00:40:13,444 --> 00:40:14,308 But the cave grew, 478 00:40:14,545 --> 00:40:17,844 until Flint Ridge alone was pushed to nearly 90 miles. 479 00:40:18,983 --> 00:40:21,042 And if it could be connected to Mammoth, 480 00:40:21,285 --> 00:40:24,015 then this was the underground Everest 481 00:40:24,288 --> 00:40:26,916 by far the longest cave in the world. 482 00:40:28,559 --> 00:40:30,322 In the summer of 1972 483 00:40:30,561 --> 00:40:34,361 a team entered Flint Ridge to probe a tantalizing passage 484 00:40:34,598 --> 00:40:36,657 that led toward Mammoth. 485 00:40:37,635 --> 00:40:41,469 It took seven hours to reach the end of the known passage. 486 00:40:42,473 --> 00:40:46,068 Then they tackled what would be called the Tight Spot. 487 00:40:46,710 --> 00:40:48,769 It seemed impenetrable. 488 00:40:54,885 --> 00:40:58,286 But one of the team had a knack for narrow places 489 00:40:58,522 --> 00:41:02,891 Pat Crowther a computer programmer and mother of two. 490 00:41:03,327 --> 00:41:05,522 Well, it never occurred to anyone to try to go through that place. 491 00:41:05,763 --> 00:41:10,393 It was a crazy place to even think that you could get your body into. 492 00:41:10,835 --> 00:41:12,996 The 'Tight Sport was a very tiny, 493 00:41:13,237 --> 00:41:19,005 vertical crevice out the bottom of a small indentation in the floor. 494 00:41:19,810 --> 00:41:23,610 And if you just casually looked down into the hole and saw that crack, 495 00:41:23,848 --> 00:41:26,408 you would say no one could possibly fit in there. 496 00:41:28,586 --> 00:41:31,487 Somehow Crowther squirmed through. 497 00:41:32,590 --> 00:41:33,648 Six weeks later, 498 00:41:33,891 --> 00:41:36,553 miles beyond where anyone had gone before, 499 00:41:36,994 --> 00:41:39,986 a chilling but significant discovery was made. 500 00:41:41,699 --> 00:41:45,430 In a mud bank were the initials P.H., 501 00:41:45,669 --> 00:41:49,332 scratched there by Pete Hanson, a long-dead tour guide. 502 00:41:49,974 --> 00:41:54,138 He could have come here only from the Mammoth Cave side. 503 00:41:55,713 --> 00:41:58,147 Carpenter Richard Zopf was in the group 504 00:41:58,382 --> 00:42:00,612 and recalls the impact of the discovery. 505 00:42:00,918 --> 00:42:02,647 We had the feeling that we had found 506 00:42:02,887 --> 00:42:04,855 ...the passage that was going to take us into Mammoth Cave, 507 00:42:05,089 --> 00:42:06,147 but we hadn't done it. 508 00:42:06,390 --> 00:42:09,052 We seen virtually a mile of passage 509 00:42:09,293 --> 00:42:11,557 but we didn't know exactly where it went. 510 00:42:11,962 --> 00:42:14,453 And we plugged along and we plodded along 511 00:42:14,698 --> 00:42:17,462 and we surveyed and we surveyed and we surveyed. 512 00:42:17,968 --> 00:42:20,266 Ten days later the group tried again, 513 00:42:20,638 --> 00:42:25,166 reaching what they now called Hanson's Lost River in nine hours. 514 00:42:26,844 --> 00:42:32,009 Excitement and exhaustion dominated the thoughts of leader John Wilcox. 515 00:42:32,249 --> 00:42:36,777 The worst thing we feared was that the passage would descent 516 00:42:37,021 --> 00:42:39,387 so that the water would come clear to the ceiling, 517 00:42:39,623 --> 00:42:41,955 and it sure looked like that was what was happening. 518 00:42:42,192 --> 00:42:43,819 The water was getting deeper and deeper 519 00:42:44,061 --> 00:42:46,325 and the ceiling was coming down. 520 00:42:46,564 --> 00:42:48,225 We're getting bent over, 521 00:42:48,465 --> 00:42:50,524 scrunching our backs up against the ceiling, 522 00:42:50,768 --> 00:42:53,032 trying to keep from getting our chests wet. 523 00:42:53,737 --> 00:42:58,106 And it was getting so wet that I told the rest of the party to wait here... 524 00:42:58,342 --> 00:42:59,639 I'm going to look ahead a little bit. 525 00:42:59,877 --> 00:43:01,344 Because I know if I get completely wet 526 00:43:01,579 --> 00:43:04,309 I can get out of the cave, but I wasn't sure everybody else could 527 00:43:05,649 --> 00:43:08,311 And just go as far as I can and trying very carefully 528 00:43:08,552 --> 00:43:15,253 not to get my chest wet and not to put my light out and so forth. 529 00:43:16,193 --> 00:43:17,455 I don't have a good sense of the time 530 00:43:17,695 --> 00:43:21,688 but John only went a few feet, went ahead for 30 seconds. 531 00:43:21,932 --> 00:43:23,866 And then there was a pause and it's like: 532 00:43:24,101 --> 00:43:25,125 What's happening, John? 533 00:43:25,369 --> 00:43:27,030 And John says: 534 00:43:27,271 --> 00:43:29,705 You know the passage is opening up! 535 00:43:29,940 --> 00:43:32,431 And, well, you know: Should we come ahead? ' 536 00:43:32,676 --> 00:43:35,611 From that low point the passage just immediately opens 537 00:43:35,846 --> 00:43:38,644 into the huge Echo River passage... 538 00:43:38,949 --> 00:43:41,281 and eventually my eyes adjusted enough 539 00:43:41,518 --> 00:43:44,612 I could begin to see a wall clear across the passage, 540 00:43:44,855 --> 00:43:46,982 a hundred feet away perhaps. 541 00:43:47,224 --> 00:43:50,819 And there was a bright, shining, 542 00:43:51,061 --> 00:43:53,529 horizontal line along the wall, 543 00:43:53,764 --> 00:43:55,891 which is something you don't see in a cave. 544 00:43:56,266 --> 00:43:57,961 You don't see any straight lines. 545 00:43:58,202 --> 00:43:59,931 And it had these vertical lines underneath 546 00:44:00,170 --> 00:44:01,330 and I realized that was a handrail. 547 00:44:01,572 --> 00:44:03,597 We had come out on a tourist trail! 548 00:44:03,974 --> 00:44:07,171 All of sudden John shouted: I see a tourist trail! 549 00:44:07,845 --> 00:44:09,745 And those words just electrified the party. 550 00:44:09,980 --> 00:44:11,811 It was kind of like someone yelling Fire! In a theater. 551 00:44:12,049 --> 00:44:14,176 Everybody just surged forward... 552 00:44:14,418 --> 00:44:18,912 ...and we realized that we had made the connection. 553 00:44:21,692 --> 00:44:23,717 Achieving the dream of decades, 554 00:44:23,961 --> 00:44:27,920 they had connected two great subterranean systems. 555 00:44:28,165 --> 00:44:33,102 Today, it is a cave with 340 miles of passageways. 556 00:44:35,272 --> 00:44:37,900 It's one of these, you know, 557 00:44:38,142 --> 00:44:40,576 complete victories that you don't often achieve in life. 558 00:44:40,811 --> 00:44:46,374 Usually things are shades of gray in your professional work 559 00:44:46,617 --> 00:44:53,113 or your personal relations with other people or whatever. 560 00:44:53,357 --> 00:44:57,157 In climbing a mountain, sometimes you have a clear-cut victory 561 00:44:57,394 --> 00:45:01,421 Either you reached the top or you didn't. 562 00:45:01,665 --> 00:45:03,394 And this was one clear-cut victory in my life where, 563 00:45:03,634 --> 00:45:05,727 by golly, we went in the Flint Ridge side 564 00:45:05,969 --> 00:45:07,960 and we came out the Mammoth Cave side 565 00:45:09,840 --> 00:45:12,934 It was a strange and lonely victory. 566 00:45:13,177 --> 00:45:16,704 After a grim struggle in the dark, subterranean river, 567 00:45:16,947 --> 00:45:20,041 they emerged in Mammoth Cave at one in the morning. 568 00:45:21,018 --> 00:45:23,646 Not even a watchman was there to greet them 569 00:45:23,887 --> 00:45:25,821 as they trudged into one of the most famous 570 00:45:26,056 --> 00:45:30,584 tourist landmarks underground the Snowball Dining Room. 571 00:45:31,261 --> 00:45:33,195 And they would complete their historic trek 572 00:45:33,430 --> 00:45:38,663 with sublime ease riding to the surface in an elevator. 573 00:45:41,705 --> 00:45:45,141 There was no fanfare, no waiting reporters. 574 00:45:45,375 --> 00:45:47,502 But they were still overjoyed. 575 00:45:47,745 --> 00:45:51,010 Like all cavers, in victory or defeat, 576 00:45:51,248 --> 00:45:54,274 they were used to being on their own. 577 00:46:00,624 --> 00:46:02,922 Beneath the New Mexican desert, 578 00:46:03,160 --> 00:46:06,596 the National Geographic expedition to Lechuguilla 579 00:46:06,830 --> 00:46:10,027 Begins its second week underground. 580 00:46:12,836 --> 00:46:15,964 The cave's beauty is now legendary, 581 00:46:16,206 --> 00:46:17,833 but there is more to discover here. 582 00:46:18,709 --> 00:46:23,612 High on a hill deep within the heart of the cave, a mystery unfolds. 583 00:46:24,481 --> 00:46:28,383 Sulfur is prevalent here and in other regions of the cave. 584 00:46:29,119 --> 00:46:32,646 And tiny bacteria are found in these deposits along 585 00:46:32,890 --> 00:46:34,881 with fungi that feed on them. 586 00:46:35,192 --> 00:46:38,457 In turn, the bacteria may feed on the sulfur, 587 00:46:38,695 --> 00:46:40,890 thriving in eternal darkness. 588 00:46:42,866 --> 00:46:45,994 Evidence indicates an unusual genesis for Lechuguilla. 589 00:46:46,870 --> 00:46:49,600 As hydrogen sulfide rose from below, 590 00:46:49,840 --> 00:46:54,334 it mixed with oxygen in water or air, forming sulfuric acid. 591 00:46:55,145 --> 00:46:58,706 This potent chemistry gradually ate through the limestone, 592 00:46:59,016 --> 00:47:01,985 creating the cave from the bottom up. 593 00:47:08,692 --> 00:47:11,183 Lechuguilla's vulnerability to human impact 594 00:47:11,428 --> 00:47:15,524 may preclude it from ever becoming a public show cave. 595 00:47:17,134 --> 00:47:20,592 A profound respect for the cave is shared by most cavers 596 00:47:20,838 --> 00:47:22,965 and severely enforced. 597 00:47:26,944 --> 00:47:30,038 Special shoes are worn for traversing formations where boots 598 00:47:30,280 --> 00:47:33,272 may mar exquisite flowstone. 599 00:47:48,165 --> 00:47:52,499 Stalagmites of calcite line the shores of the Pearlsian Gulf, 600 00:47:52,903 --> 00:47:57,397 so called because of the thousands of pearl-like formations found here. 601 00:48:04,581 --> 00:48:06,515 Looking like fried eggs, 602 00:48:06,750 --> 00:48:10,846 this kind of cave pearl is built up from calcite in the water. 603 00:48:12,356 --> 00:48:16,986 Another variety of cave pearl forms when a single grain of sand 604 00:48:17,227 --> 00:48:19,127 becomes coated with calcite. 605 00:48:20,697 --> 00:48:25,031 Over time the relentless dripping of water swivels the grain 606 00:48:25,269 --> 00:48:26,793 and the coating becomes thicker, 607 00:48:27,337 --> 00:48:29,737 like the creation of a pearl in an oyster. 608 00:48:35,245 --> 00:48:38,908 Lake Castrovalva guards a remote corner of the cave. 609 00:48:39,549 --> 00:48:42,484 The only way across is to swim. 610 00:48:43,220 --> 00:48:47,850 But the conservation creed demands that no dirty clothing soil its purity 611 00:49:05,342 --> 00:49:10,541 The air and water temperatures are the same year round 68 degrees. 612 00:49:33,403 --> 00:49:37,100 Intricate stone formations border the edge of the lake, 613 00:49:37,341 --> 00:49:40,367 slowly deposited by waters rich in calcite. 614 00:49:41,411 --> 00:49:45,871 For eons these exotic shores have been still and silent 615 00:49:46,717 --> 00:49:49,083 calm until now. 616 00:49:57,594 --> 00:49:59,061 Light on the station. 617 00:49:59,329 --> 00:50:03,823 The primary function of any expedition is to explore and survey the cave 618 00:50:04,334 --> 00:50:06,063 to produce a detailed map. 619 00:50:07,904 --> 00:50:12,432 Keeping accurate records is virtually a religion for modern cavers. 620 00:50:13,677 --> 00:50:14,507 Two thirty-nine, point five. 621 00:50:14,745 --> 00:50:18,943 It's what separates them from earlier, less responsible explorers underground 622 00:50:19,950 --> 00:50:20,678 Plus four. 623 00:50:20,951 --> 00:50:21,508 Plus four. 624 00:50:21,885 --> 00:50:25,377 Finding something new is the first great thrill of caving. 625 00:50:25,822 --> 00:50:28,814 The second comes later finding the way out. 626 00:50:29,960 --> 00:50:33,828 Each night the latest survey date are typed into the computer 627 00:50:34,297 --> 00:50:36,026 to produce an updated map. 628 00:50:41,605 --> 00:50:44,506 The ancient skeleton of a ring-tailed cat. 629 00:50:46,243 --> 00:50:49,872 Kiym Cunningham examines one of the riddles of Lechuguilla. 630 00:50:50,480 --> 00:50:53,847 It's a mystery. I mean, altogether it's a mystery how he got down here. 631 00:50:54,084 --> 00:50:56,814 We're a thousand feet below the surface. 632 00:50:57,087 --> 00:51:00,056 Many vertical pits and long passages to get here. 633 00:51:00,290 --> 00:51:03,259 So, he was a heck of a caver! 634 00:51:03,493 --> 00:51:07,361 He evidently died right on the margin of this old pool system here, 635 00:51:07,597 --> 00:51:10,725 so I would imagine possibly he was alive when he was down here, 636 00:51:10,967 --> 00:51:12,457 came to the pool to drink. 637 00:51:12,702 --> 00:51:15,000 Only source of water he could find. 638 00:51:15,238 --> 00:51:17,468 And maybe the mineral content was very high. 639 00:51:17,707 --> 00:51:21,734 It was not a good pool to drink from and that may have been what killed him 640 00:51:26,149 --> 00:51:28,947 The amount of carbon dioxide in the cave atmosphere is measured. 641 00:51:29,186 --> 00:51:34,624 If the level down here is the same as on the surface, 642 00:51:35,125 --> 00:51:38,856 it could indicate other openings yet to be discovered. 643 00:51:40,864 --> 00:51:44,095 Somewhere within the cave's vast system 644 00:51:44,468 --> 00:51:49,405 the air is being disturbed. There is noticeable movement. 645 00:51:50,874 --> 00:51:55,641 Still, Lechuguilla refuses to yield its secrets easily. 646 00:51:56,146 --> 00:52:00,139 It remains alien and strangely beautiful, 647 00:52:00,383 --> 00:52:03,682 a landscape from another world. 648 00:52:35,852 --> 00:52:38,616 Lechugulla's wonder is a fragile thing 649 00:52:38,855 --> 00:52:42,154 What man can discover, he can easily destroy. 650 00:52:43,093 --> 00:52:45,994 Most of us may never see these enchanting caverns 651 00:52:46,463 --> 00:52:49,159 and others that lie still undiscovered. 652 00:52:50,100 --> 00:52:54,161 But perhaps it will be enough to know that they are there. 653 00:52:55,238 --> 00:52:58,639 Lechuguilla now consists of almost 60 miles 654 00:52:58,875 --> 00:53:01,139 of breathtaking passageways. 655 00:53:01,645 --> 00:53:06,548 New discoveries continue and there is no end in sight.