The thrill of pushing forward to discover what is there.
Jan Conn, Jewel Cave explorer. ca. 1975
Buried beneath the Black Hills of South Dakota is the fascinating underground world of Jewel Cave. It delights, it perplexes, and always it lures you on and on to further explorations: to see a chamber decorated with glittering calcite crystals; to sample the outstanding variety of beautiful, colorful, and strange cave formations for which Jewel Cave is famous; or to experience a small part of its more than 130 miles of intricate maze-like passages. Discover the spirit of adventure in Jewel Cave.
In 1908, when Jewel Cave National Monument was established, only a few of the wonders of Jewel Cave had been discovered. Less than ½ mile of passages was known then and the primary attractions were chambers of jewel-like calcite crystals. Explorations in the past 30 years have revealed many more of Jewel Cave's underground delights. Because the cave is a scientific gem, much of it is set aside for research and is not open to the public. But tour routes have been designed so you can experience some of the best of Jewel Cave.
On a tour you can begin to sense that Jewel Cave is not the small cave it was once thought to be. It is the world's third longest known cave, a labyrinth that twists and turns for more than 130 miles below the surface. Its creation took millions of years, starting with the formation of the Black Hills, when mountain-building forces created faults in the Earth. Beginning 30 to 50 million years ago, slightly acidic groundwater seeped into these faults, dissolving the surrounding Mississippian-aged Pahasapa Limestone and, over a period of several million years, hollowing out the passages of Jewel Cave. A variety of cave formations was created during the later stages of cave development; you will see some of these on your cave tour. Many of these splendid formations are described below.
Drop by Drop
Among Jewel Cave's many formations are those that have been created by water dripping or trickling into the cave. Millions of particles of the mineral calcite deposited from millions of water droplets make up each formation. Where drops fell from the ceiling, stalactites have formed; where they hit the floor, stalagmites have grown; and where stalactites and stalagmites have merged, columns have appeared. Water trickling down a slanted ceiling has created translucent draperies, while water flowing over a wall has left behind deposits of flowstone. The Scenic and Spelunking Tours have examples of some of these beautiful and sometimes colorful features. Where water continues to seep into the cave, these formations are still taking shape.
Jewel Cave got its name because of many of its rooms and passages are lined with jewel-like crystals, some of which sparkle like brilliant gems when illuminated. This extraordinary and impressive underground spectacle is created by Jewel Cave's most abundant cave formations - the calcite crystals known as dog-tooth spar and nailhead spar.
Remarkable and Rare
Jewel Cave's collection of underground formations includes some that are especially rare and unusual. Helictites are one such oddity. Only a few inches long, they twist and turn in all directions without regard for gravity. Like most cave formations, helictites are made up of calcite, as is popcorn, which grows in small knobby clusters. Delicate, needle-like cave decorations known as frostwork can be composed of calcite or a similar mineral called aragonite. Criss-crossing patterns of calcite veins called boxwork also occur in Jewel Cave, although they are more abundant in nearby Wind Cave. Another mineral - gypsum - fancifully appears in the shape of flowers, needles, spiders, and cottony beards. Scintillites, a type of formation unknown until discovered in Jewel Cave, are composed of the reddish rock called chert and a coating of sparkling clear quartz crystals. Two other particularly intriguing discoveries in Jewel Cave are hydromagnesite balloons - fragile silvery bubbles only a few inches in diameter - and moonmilk, a powdery substance resembling cottage cheese. You may see some of these extraordinary formations on a Jewel Cave tour.
Exploring Jewel Cave
The exploration of Jewel Cave began about 1900 when two South Dakota prospectors, Frank and Albert Michaud, and a friend, Charles Bush, happened to hear wind rushing through a hole in the rocks in Hell Canyon. Enlarging the hole, they found a cave full of sparkling crystals. They filed a mining claim on the "Jewel Lode," but they found no valuable minerals, so they tried turning the cave into a tourist attraction instead. The business was never a success, but the cave did attract attention, and in 1908 Jewel Cave National Monument was established to protect the small but extraordinary beautiful cave. Fifty years later exploration of the cave suddenly intensified. Led by the husband-and-wife team of Herb and Jan Conn, modern-day cavers have discovered new wonders and more than 80 miles of passages. Today the cave is among the world's longest and is renowned for its variety of formations.
Into the Unknown
When Herb and Jan Conn were first persuaded to join a caving expedition in Jewel Cave in 1959, the couple responded without enthusiasm. Their passion was rock climbing, not crawling around in dark, gloomy holes. Little did they know they would spend much of the next 21 years in Jewel Cave, lured by the thrill of discovering the secrets of yet another mile of never before-seen cave. The caving parties led by this husband-and-wife team would make 708 trips into the cave and log 6,000 hours exploring and mapping.
Our exploration of Jewel Cave, which started out as a mild diversion, quickly mushroomed into an all-absorbing interest," the Conns explain in their book The Jewel Cave Adventure. On a typical day, the Conns and their fellow cavers spent 12 to 14 hours underground. Outfitted in hard hats, carbide lamps, gloves, loose fatigues, elbow and knee pads, and boots, the explorers squeezed, crawled, and climbed their way through Jewel Cave's complicated maze. The going was rough. During rest stops they munched on mangled sandwiches and squashed fruit while massaging sore muscles. Names they gave to some passages, such as Contortionist's Delight and The Miseries, tell the story.
As years passed and more miles of cave were found, it became apparent that Jewel Cave was one of the world's most extensive caves, full of scenic and scientific wonders. The explorers found chambers with exquisite calcite crystals and rare cave formations. One much-decorated room discovered by the Conns - the Formation Room - is a highlight of the Scenic Tour today. They also found rooms as large as 150 by 200 feet, passageways as long as 3,200 feet, and a place where the cave wind blows at speeds of up to 32 miles per hour. The cave, they discovered, is truly a rare and precious jewel.
In 1980, after discovering more than 65 miles of cave, the Conns retired. A new generation of cavers has already pushed the known boundaries of the cave to more than 80 miles. But the mystery remains. As the Conns have said, "We are still just standing on the threshold."
The General park map handed out at the visitor center is available on the park's map webpage.For information about topographic maps, geologic maps, and geologic data sets, please see the geologic maps page.
A photo album for this park can be found on the park's webpage. For information on other photo collections featuring National Park geology, please see the Image Sources page.
Currently, we do not have a listing for a park-specific geoscience book. The park's geology may be described in regional or state geology texts.
Parks and Plates: The Geology of Our National Parks, Monuments & Seashores.
Lillie, Robert J., 2005.
W.W. Norton and Company.
9" x 10.75", paperback, 550 pages, full color throughout
The spectacular geology in our national parks provides the answers to many questions about the Earth. The answers can be appreciated through plate tectonics, an exciting way to understand the ongoing natural processes that sculpt our landscape. Parks and Plates is a visual and scientific voyage of discovery!
Ordering from your National Park Cooperative Associations' bookstores helps to support programs in the parks. Please visit the bookstore locator for park books and much more.
For information about permits that are required for conducting geologic research activities in National Parks, see the Permits Information page.
The NPS maintains a searchable data base of research needs that have been identified by parks.
A bibliography of geologic references is being prepared for each park through the Geologic Resources Evaluation Program (GRE). Please see the GRE website for more information and contacts.
NPS Geology and Soils PartnersAssociation of American State Geologists
Geological Society of America
Natural Resource Conservation Service - Soils
U.S. Geological Survey
Currently, we do not have a listing for any park-specific geology education programs or activities.
General information about the park's education and intrepretive programs is available on the park's education webpage.For resources and information on teaching geology using National Park examples, see the Students & Teachers pages.