| Jewel Cave National Monument | |
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.jpg) Visitors and guide inside Jewel Cave | |
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| Location | Custer County, South Dakota,U.S. |
| Nearest city | Custer, South Dakota |
| Coordinates | 43°43′46″N103°49′46″W / 43.72944°N 103.82944°W /43.72944; -103.82944 |
| Area | 1,273 acres (5.15 km2)[1] |
| Created | February 7, 1908 (1908-02-7) |
| Visitors | 137,275 (in 2016)[2] |
| Governing body | National Park Service |
| Website | Jewel Cave National Monument |
Jewel Cave National Monument containsJewel Cave, currently thefifth longest cave in the world and second longest cave in the United States, with 220.01 miles (354.07 km) of mapped passageways as of May 2024.[3][4][5] It is located approximately 13 miles (21 km) west of the town ofCuster inBlack Hills ofSouth Dakota. It became anational monument in 1908.[6]
Frank and Albert Michaud, two local prospectors, discovered the cave in 1900, when they felt cold air blowing out of a small hole in a canyon. It is unknown whether any previous inhabitants of the area were aware of the natural cave opening, which was not large enough for a person to enter.[7]
After enlarging the cave entrance with dynamite, the Michaud brothers found a cavern lined withcalcite crystals, which led them to name it "Jewel Cave". The brothers tried to capitalize on the discovery, widening the opening, building walkways inside, and opening it to tourists. Although their venture was unsuccessful, news of the discovery eventually reached Washington. PresidentTheodore Roosevelt proclaimed Jewel Cave a National Monument on February 7, 1908. The area around the natural entrance to the cave was further developed by theCivilian Conservation Corps in the 1930s. TheNational Park Service assumed management of the monument in 1933 and began offering tours in 1939.[7]
As recently as 1959, less than 2 miles (3.2 km) of passageway had been discovered. That year, however,Herb and Jan Conn, local rock climbers, began exploring, and within two years had mapped 15 miles (24 km). Much of the new discoveries lay outside the boundaries of the monument, under land managed by theUnited States Forest Service. The two agencies performed a land swap in 1965, establishing the present boundaries of the park, and enabling the development of a new part of the cave. The Park Service sunk a 300 feet (91 m) elevator shaft to a previously remote cave area, and built concrete walks and metal stairs and platforms along a one-half-mile loop. The "Scenic Tour" was opened in 1972. Most modern-day visitors tour that part of the cave. In August 2000, an 83,000 acres (340 km2)forest fire burned 90% of the monument and the surrounding area. Thevisitor center and historic buildings were spared.
By 1979,Herb and Jan Conn had discovered, named, and mapped more than 64 miles (103 km) of passages. Although they largely retired from caving by the early 1980s, exploration has continued unabated. Because the areas being explored take many hours to reach, explorers now sometimes camp in the cave during expeditions of as long as four days. The cave is mapped by traditional survey techniques, usingcompass,clinometer and today with lasers instead of tape measures.[7]
Its near 220 mi (350 km) of mapped passageway make Jewel Cave the fifth longest cave in the world, after theMammoth Cave System in Kentucky,Ox Bel Ha,Sac Actun, both in theYucatán Peninsula (Mexico)[3] andShuanghedong Cave Network in China.
The discovered areas in the cave account for only about 3–5% of the estimated total air volume of the cave, which is believed to be roughly 8 billion cubic feet (230 million cubic meters).[8] This puts estimates for the total length somewhere between roughly 4,400 miles (7,100 km) and 7,300 miles (11,700 km). The cave volume is estimated by measuring the amount of air that the cave "exhales" when the outside air pressure drops and "inhales" when the outside air pressure rises.[7]
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| SouthwesternSouth Dakota |
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| Sculptures |
| Geologic and natural history |
| Mountains |
| Caves |
| Forests and wildernesses |
| Lakes |
| Long-distance trails |
| Scenic byways |
| Historic sites |
Jewel Cave is a "breathing cave," which means air enters or exits the cave with changes inatmospheric pressure from day to night or due to changes in the weather.[9] This was first explained by Herb Conn in 1966.[10][11]
Most of the cave formed within theMississippian PahasapaLimestone deposited 350 million years ago. The later limestones,sandstones, andshales deposited in thesePaleozoic andMesozoic seas were eroded with thegeologic uplift associated withLaramide Orogeny and the formation of theBlack Hills. The main passages of the cave then formed in the earlyCenozoic. Uplift continued in theLate Pliocene orEarly Pleistocene lowering thewater table and draining the cave.[11]: 29–30
Jewel Cave passages follow a pattern ofjoint development. The faults and joints are associated with the uplift of the Black Hills approximately 58 to 54 million years ago. After main cavedissolution, a thick layer ofcalcite lined the walls about 2.5 million years ago.[11]: 12
During cave development and afterwards,speleothems andspeleogens formed, including the "jewels" orspar. Other examples includestalactites,stalagmites,flowstone,cave popcorn,boxworks,helictites, scintillites, conulites, coralloids,cave pearls,rimstone, rafts, rims, vents, andfrostwork. Thegypsum formations include needles, beards, cotton, hair, flowers, and spiders. Finally, Jewel Cave contains a very rare formation called ahydromagnesite balloon. Those are created when gas of an unknown source inflates a pasty substance formed by the precipitation of the magnesium carbonate hydroxide mineral.[11]: 14–18
Jewel Cave is located less than 20 miles fromWind Cave National Park, though the caves are not believed to be connected.[12]
Jewel Cave is open year-round. The Park Service offers three tours: the scenic tour, a half-mile loop through a paved and lighted central portion of the cave accessible by elevator; the historic tour, a candlelight tour through the earliest-discovered part of the cave; and a wild caving tour, through an undeveloped part of the cave near the scenic loop. There are 3 surface trails varying in length and difficulty.[7]
Media related toJewel Cave National Monument at Wikimedia Commons
Jewel Cave National Monument travel guide from Wikivoyage| International | |
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