View source for Jewel Cave National Monument

{{Short description|Cave in the Black Hills of South Dakota, USA}}
{{Use mdy dates|date=February 2025}}
{{Infobox protected area 
| name = Jewel Cave National Monument
| iucn_category = III
| photo = File:Scenic Tour Route.JPG
| photo_caption = The Inner Sanctum, one of the longest and largest passageways along the Scenic Tour
| photo_width     = 250
| map = South Dakota#USA
| relief = 1
| map_caption = 
| location = [[Custer County, South Dakota]], [[United States|U.S.]]
| nearest_city = [[Custer, South Dakota]]
| coordinates = {{coord|43|43|46|N|103|49|46|W|region:US|display=inline, title}}
| area_acre = 1273
| area_ref = <ref name="area">{{NPS area |year=2011 |accessdate=2012-04-03}}</ref>
| created = {{start date|1908|02|7}}
| visitation_num = 145,332
| visitation_year = 2024
| visitation_ref = <ref name="visits">{{NPS visitation |accessdate=2025-07-06}}</ref>
| governing_body = [[National Park Service]]
| website = [https://www.nps.gov/jeca/index.htm Jewel Cave National Monument]
}}
'''Jewel Cave National Monument''' contains '''Jewel Cave''', currently the [[List of longest caves|fifth longest cave]] in the world and second longest cave in the United States, with {{convert|220.33|mi|km}} of mapped passageways as of July 2025.<ref name="NPS">{{Cite web |title=Cave Exploration - Jewel Cave National Monument (U.S. National Park Service) |url=https://www.nps.gov/jeca/learn/nature/caveexploration.htm |access-date=2025-07-27 |website=www.nps.gov |language=en}}</ref><ref name="NewsCenter">{{cite web | title = Explorers return to mapping Jewel Cave after two-year hiatus | publisher = NewsCenter 1 | url = https://www.newscenter1.tv/explorers-return-to-mapping-jewel-cave-after-two-year-hiatus/ | date = November 5, 2021 | access-date = May 22, 2022}}</ref><ref name="JECA">{{cite web | title = Jewel Cave Reaches 200 Miles | publisher = [[National Park Service]] (NPS) | url = https://www.nps.gov/jeca/learn/news/jewel-cave-reaches-200-miles.htm | date = December 19, 2018 | access-date = December 19, 2018}}</ref> It is located approximately {{convert|13|miles|km}} west of the town of [[Custer, South Dakota|Custer]] in the [[Black Hills]] of [[South Dakota]].

Jewel Cave became a [[U.S. National Monument|national monument]] in 1908, becoming the first national monument established for the protection and preservation of a cave.<ref name="index">{{cite web |url=http://www.nps.gov/history/history/online_books/nps/nps/part2.htm#jeca |archive-url=https://web.archive.org/web/20091027041334/http://www.nps.gov/history/history/online_books/nps/nps/part2.htm#jeca |url-status=dead |archive-date=October 27, 2009 |title=The National Parks: Index 2009–2011 |publisher=[[National Park Service]] |access-date=2012-04-02}}</ref><ref name="foundation">{{cite web |url=https://npshistory.com/publications/foundation-documents/jeca-fd-2016.pdf |archive-url=https://web.archive.org/web/20250405192450/https://npshistory.com/publications/foundation-documents/jeca-fd-2016.pdf |archive-date=April 5, 2025 |title=Foundation Document - Jewel Cave National Monument, South Dakota |publisher=[[National Park Service]] |access-date=2025-07-28}}</ref> In addition to its length, the cave is significant for being one of the best known examples of a [[breathing cave]], in which changes in outside air pressure cause air to flow into and out of the cave. Jewel Cave is named for the [[calcite]] crystals that cover many of its walls.<ref name=Formations>{{Cite web |title=Formations - Jewel Cave National Monument (U.S. National Park Service) |url=https://www.nps.gov/jeca/formations-of-jewel-cave.htm |access-date=2025-07-28 |website=www.nps.gov |language=en}}</ref>

==Mission==
The monument's mission is stated in its foundation document:<ref name=foundation />
{{Blockquote
|text=The purpose of Jewel Cave National Monument is to preserve, protect, and interpret one of the last great frontiers by managing and exploring an extensive cave system and the overlying surface for continued scientific and personal interest, and for inspiring public discovery.
}}

==History==
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.<ref name="brochure">Jewel Cave brochure; National Park Service; GPO, WDC</ref>

After enlarging the cave entrance with dynamite, the Michaud brothers found a cavern lined with [[calcite]] 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 and they had to sell their mining claim back to the government, news of the discovery eventually reached Washington. President [[Theodore Roosevelt]] proclaimed Jewel Cave a national monument on February&nbsp;7, 1908. The area around the natural entrance to the cave was further developed by the [[Civilian Conservation Corps]] in the 1930s. The [[National Park Service]] assumed management of the monument from the [[United States Forest Service]] in 1933 and began offering tours in 1939.<ref name="brochure" />
[[File:Visitor at Historic Area (f6887dcc-b654-1efe-84c5-086cac37cb38).jpg|thumb|left|A mid-century visitor to Jewel Cave]]

As recently as 1959, less than {{convert|2|mi|km}} of passageway had been discovered. That year, however, [[Jan and Herb Conn]], local rock climbers, began exploring, and within two years had mapped {{convert|15|mi|km}}.
[[File:Jan Conn in Jannies Cranny, Jewel Cave - 1959.jpg|thumb|Jan Conn exploring Jewel Cave in 1959]]

Much of the new discoveries lay outside the boundaries of the monument, under land managed by the Forest Service. The two agencies performed a [[land exchange|land swap]] in 1965, establishing the present boundaries of the park and enabling the development of a new part of the cave. The National Park Service sunk a {{convert|300|ft|m}} elevator shaft to a previously remote cave area, and built concrete walks and metal stairs and platforms along a half-mile loop. The "Scenic Tour" was opened in 1972. Most modern-day visitors tour that part of the cave.

In August 2000, the [[2000 Jasper Fire|Jasper Fire]], an {{convert|83000|acre|km2|abbr=on}} [[forest fire]], burned 90% of the monument and the surrounding area. The [[visitor center]] and historic buildings were spared.

==Exploration==
[[File:Herb and Jan Conn at Jewel Cave NM.png|thumb|left|Herb and Jan Conn at Jewel Cave in 1959]]

By 1979, [[Jan and Herb Conn]] had discovered, named, and mapped more than {{convert|64|mi|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. Three permanent camps have been established at various locations within the cave.<ref name=NPS /> Today the cave is mapped by traditional survey techniques, using [[compass]]es, [[clinometer]]s, and [[Laser rangefinder|lasers]] instead of tape measures.<ref name="brochure" />

[[File:Black Hills uplift diagram.png|thumb|upright|Location of the cave with respect to regional Black Hills geology]]
Its over {{convert|220|mi|km}} of mapped passageway make Jewel Cave the fifth longest cave in the world, after the [[Mammoth Cave|Mammoth Cave System]] in Kentucky, [[Sistema Ox Bel Ha]] and [[Sistema Sac Actun]], both in the [[Yucatán Peninsula]] ([[Mexico]]), and [[Shuanghedong Cave Network]] in China. All currently known passages of Jewel Cave fit within a {{convert|4|mi2|km2}} surface area. The elevation range of the cave is {{convert|822|ft|m}}, with its deepest known point approximately {{convert|600|ft|m}} below the surface. The largest room discovered in Jewel Cave is the Big Duh, which is {{convert|570|ft|m}} long and averages {{convert|90|-|180|ft|m}} wide and {{convert|30|ft|m}} high.<ref name=NPS />

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 {{convert|8|e9ft3|e6m3|abbr=off|sp=us}}.<ref>{{Cite web |date=2016-02-27 |title=When you explore Jewel Cave and Wind Cave in South Dakota, revelations may be around the next corner |url=https://www.latimes.com/travel/la-tr-d-nps-caverns-20160215-htmlstory.html |access-date=2024-01-18 |website=Los Angeles Times |language=en-US}}</ref> This puts estimates for the total length somewhere between roughly {{convert|4,400|mi|km}} and {{convert|7,300|mi|km}}.<ref name=Research>{{Cite web |title=Science & Research - Jewel Cave National Monument (U.S. National Park Service) |url=https://www.nps.gov/jeca/learn/scienceresearch.htm |access-date=2025-07-27 |website=www.nps.gov |language=en}}</ref> 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.<ref name="brochure" />

==Geology==
{{Black Hills and Badlands}}
Jewel Cave is a [[solutional cave]] formed primarily in [[limestone]]. Most of the cave formed within the [[Pahasapa Formation]] deposited during the [[Mississippian (geology)|Mississippian]], approximately 350 million years ago.  The later limestones, [[sandstone]]s, and [[shale]]s deposited in these [[Paleozoic]] and [[Mesozoic]] seas, known collectively as the [[Minnelusa Formation]], were eroded with the [[geologic uplift]] associated with [[Laramide Orogeny]] and the formation of the [[Black Hills]].  The main passages of the cave then formed in the early [[Cenozoic]].  Uplift continued in the [[Late Pliocene]] or [[Early Pleistocene]], lowering the [[water table]] and draining the cave.<ref name=Keller/>{{rp|29–30}}

Jewel Cave passages follow a pattern of [[joint (geology)|joint]] development. The faults and joints are associated with the uplift of the Black Hills approximately 58 to 54 million years ago.  After main cave [[dissolution (chemistry)|dissolution]], a thick layer of [[calcite]] lined the walls about 2.5 million years ago.<ref name=Keller/>{{rp|12}}

During cave development and afterwards, [[speleothem]]s and [[speleogen]]s formed, including the "jewels" or [[spar (mineralogy)|spar]].<ref name=Formations /> Other examples include [[stalactite]]s, [[stalagmite]]s, [[soda straw]]s, [[flowstone]], [[cave popcorn]], [[boxwork]], [[helictite]]s, scintillites, conulites, logomites, [[cave pearl]]s, [[rimstone]], rafts, rims, vents, and [[frostwork]].  The [[gypsum]] formations include needles, beards, cotton, hair, flowers, and spiders. Finally, Jewel Cave contains a very rare formation called a [[hydromagnesite]] balloon. Those are created when gas of an unknown source inflates a pasty substance formed by the precipitation of the magnesium carbonate hydroxide mineral.<ref name=Keller/>{{rp|14–18}}
[[File:Hydromagnesite balloon.jpg|thumb|left|Hydromagnesite balloon in Jewel Cave]]

Jewel Cave is a [[breathing cave]], which means air enters or exits the cave with changes in [[atmospheric pressure]] from day to night or due to changes in the weather.<ref>{{Cite journal |last1=Gomell |first1=Annika |last2=Austin |first2=Daniel |last3=Ohms |first3=Marc |last4=Pflitsch |first4=Andreas |date=September 2021 |title=Air pressure propagation through Wind Cave and Jewel Cave: How do pressure waves travel through barometric caves? |url=https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=2393&context=ijs |journal=[[International Journal of Speleology]] |volume=50 |issue=3 |pages=263–273 |doi=10.5038/1827-806X.50.3.2393 |via=[[University of South Florida]] |doi-access=free}}</ref> This was first explained by [[Jan and Herb Conn|Herb Conn]] in 1966.<ref>{{Cite journal |last=Conn |first=Herbert |date=April 1966 |title=Barometric Wind in Wind and Jewel Caves, South Dakota |url=https://legacy.caves.org/pub/journal/NSS%20Bulletin/vol%2028%20part%202.pdf |journal=Bulletin of the National Speleological Society |volume=28 |issue=2 |pages=55–69}}</ref><ref name=Keller>{{cite book|last1=KellerLynn|first1=K.|title=Jewel Cave National Monument Geologic Resources Inventory Report, National Resource Report NPS/NRPC/GRD/NRR 2009/084|date=2009|publisher=US National Park.}}</ref> The temperature inside the cave is {{convert|49|F|C}} year-round.<ref name=tours>{{Cite web |title=Guided Tours - Jewel Cave National Monument (U.S. National Park Service) |url=https://www.nps.gov/jeca/planyourvisit/guidedtours.htm |access-date=2025-07-27 |website=www.nps.gov |language=en}}</ref>

Although much of Jewel Cave is dry, over a dozen [[underground lake]]s have been discovered where the cave meets the Madison Aquifer, about {{convert|600|ft|m}} below the surface. The first of these, Hourglass Lake, was discovered in 2015.<ref name=Research />

Jewel Cave is located less than {{convert|20|mi|km}} from [[Wind Cave National Park]], though the caves are not believed to be connected.<ref>{{Cite web |title=Esri News -- ArcNews Winter 2002/2003 Issue -- Developing a Cave Potential Map for South Dakota's Wind Cave Using GIS |url=https://www.esri.com/news/arcnews/winter0203articles/developing-a-cave.html |access-date=2024-01-08 |website=www.esri.com}}</ref>
{{clear left}}

==Flora and fauna==
Jewel Cave is one of the largest bat [[Hibernaculum (zoology)|hibernacula]] in the United States.<ref name=":0">{{Cite web |title=Animals - Jewel Cave National Monument (U.S. National Park Service) |url=https://www.nps.gov/jeca/learn/nature/animals.htm |access-date=2025-07-07 |website=www.nps.gov |language=en}}</ref> Thousands of bats of ten different species live in and around the cave throughout the year, including several species which hibernate in the cave during the winter. Bat numbers have decreased significantly since 2018, when the fungus that causes [[white-nose syndrome]] was first discovered in Jewel Cave.<ref name=":1">{{Cite web |title=Bats - Jewel Cave National Monument (U.S. National Park Service) |url=https://www.nps.gov/jeca/learn/nature/bats.htm |access-date=2025-07-07 |website=www.nps.gov |language=en}}</ref>

Other animals living on the surface include [[bighorn sheep]], [[mule deer]], [[white-tailed deer]], [[Cougar|mountain lions]], [[coyote]]s, [[Bushy-tailed woodrat|packrats]], [[garter snake]]s, [[Crotalus viridis|prairie rattlesnakes]], [[great horned owl]]s, [[blue jay]]s, [[red-headed woodpecker]]s, [[western tanager]]s, [[cliff swallow]]s, and occasional [[American black bear]]s and [[elk]].<ref name=":0" />

The surface of the national monument is [[ponderosa pine forest]].<ref>{{Cite web |title=Plants - Jewel Cave National Monument (U.S. National Park Service) |url=https://www.nps.gov/jeca/learn/nature/plants.htm |access-date=2025-07-07 |website=www.nps.gov |language=en}}</ref>

==Access and infrastructure==
[[File:JewelCaveNM VisitorCenter.jpg|thumb|left|Jewel Cave National Monument's main visitor center complex]]
Jewel Cave is open year-round. Surface amenities include a visitor center, park theater, natural history exhibits, park store, hiking trails, and picnic areas. To enter the cave, visitors must take a [[National Park Service ranger|ranger-guided]] tour.<ref name=tours /> Over 145,000 people visited Jewel Cave in 2024.<ref>{{Cite web |title=Stats Report Viewer |url=https://irma.nps.gov/Stats/SSRSReports/Park%20Specific%20Reports/Annual%20Park%20Recreation%20Visitation%20(1904%20-%20Last%20Calendar%20Year)?Park=JECA |access-date=2025-07-07 |website=irma.nps.gov}}</ref>

[[File:Inside Jewel Cave National Monument - (15096023561).jpg|thumb|Visitors and guide inside Jewel Cave]]
The [[National Park Service]] offers four tours seasonally: the Scenic Tour, a half-mile loop through a paved and lighted central portion of the cave accessed by elevator; the Discovery Tour, a short accessible tour to a single, large room of the cave; the Historic Lantern Tour, a lantern-lit tour through the earliest-discovered part of the cave; and the Wild Caving Tour, through an undeveloped part of the cave near the scenic loop. The Wild Caving Tour requires visitors to squeeze through a passageway less than {{convert|9|in|cm}} tall.<ref name="brochure" />

There are two surface trails varying in length and difficulty, the longer of which takes visitors through the monument's historic area and past Jewel Cave's historic entrance.<ref>{{Cite web |title=Hiking Trails - Jewel Cave National Monument (U.S. National Park Service) |url=https://www.nps.gov/jeca/planyourvisit/trails.htm |access-date=2025-07-27 |website=www.nps.gov |language=en}}</ref> The historic trail, cave entrance, and ranger station were listed in the [[National Register of Historic Places]] in April 1995.<ref>{{Cite web |title=South Dakota MPS Historic Trail and Cave Entrance |url=https://catalog.archives.gov/id/93203597 |access-date=2025-07-29 |website=catalog.archives.gov |language=en}}</ref><ref>{{Cite web |title=South Dakota MPS Ranger Station |url=https://catalog.archives.gov/id/93203609 |access-date=2025-07-29 |website=catalog.archives.gov |language=en}}</ref>

== Gallery ==
<gallery>
File:Jewel Cave National Monument 03.jpg|The historic visitor center, built by the [[Civilian Conservation Corps]] in the 1930s
File:Jewel Cave National Monument 10.jpg|Trail to Jewel Cave's historic entrance
File:Jewel Cave National Monument 19.jpg|Interior view of Jewel Cave's historic entrance
File:The Crushing Deep is currently one of the deepest known parts of Jewel Cave. (ea7f45eb-cc56-fa1c-afff-131ef8d9b0fd).JPG|The Crushing Deep, one of the deepest known parts of Jewel Cave
File:Jewel Cave 1.jpg|Much of Jewel Cave is covered with [[calcite]] spar crystals, but they are rarely as clear as this cluster.
File:Jewel Cave 2.jpg|Calcite crystals cover much of the walls in some sections of the cave. Typically they are a dull brown color as in this room.
File:Jewel Cave is a dry cave, but areas with "wet" formations such as these stalagmites and stalactites do exist. (ea3f6ae9-be6d-220e-3d57-658de86879dd).JPG|Jewel Cave is mainly a dry cave, but areas with "wet" formations such as these [[stalagmite]]s and [[stalactite]]s do exist.
File:Bacon Strip Jewel Cave koopas.JPG|Cave bacon, a type of [[Flowstone#Formation|drapery]] seen on the Scenic Tour
File:Jewel Cave 3.jpg|Aragonite [[frostwork (geology)|frostwork]] is another speleothem found throughout the cave, typically in small crusts on the walls.
File:Gypsum flowers are typically only found in dry areas of Jewel Cave. (eb8214a0-ba30-b9ad-62f7-34d22e66831e).JPG|[[Gypsum]] flowers are typically only found in dry areas of Jewel Cave.
File:A caver looks at a cave formation called a logomite. (ea1af457-04fe-082f-ada5-4d0b6fd02a07).JPG|A caver looks at a cave formation called a logomite.
</gallery>

==See also==
<!---♦♦♦ Please keep the list in alphabetical order ♦♦♦--->
* [[Lehman Caves]]
* [[Mammoth Cave National Park]]
* [[Oregon Caves National Monument and Preserve]]
* [[Russell Cave National Monument]]
* [[Speleology]]
* [[Timpanogos Cave National Monument]]
* [[Wind Cave National Park]]
* [[List of caves]]
* [[List of longest caves]]
** [[List of longest caves in the United States]]
* [[List of national monuments of the United States]]

== References ==
{{reflist}}

== Further reading ==
* {{cite book |title=The Jewel Cave Adventure: Fifty Miles of Discovery in South Dakota |first1=Herb |last1=Conn |first2=Jan |last2=Conn |year=1977 |publisher=Cave Books |isbn=0-939748-01-0}} (describes the exploration of Jewel Cave from its discovery to the mid-1980s)
* {{cite book |title=A Small Cave No More: An Administrative History of Jewel Cave National Monument, South Dakota |first1=Jackie |last1=Gonzales |first2=Emily |last2=Greenwald |year=2020 |oclc=1272899675}}
* {{cite book |title=Jewel Cave: A gift from the past |first=Arthur |last=Palmer |year=1984 |oclc=20543502}}
* {{cite book |title=The National Parks: Index 2001–2003 |location=Washington, D.C. |publisher=[[United States Department of the Interior|U.S. Department of the Interior]] |oclc=53228516}}

== External links ==
* [https://www.nps.gov/jeca/index.htm Official website] at the [https://www.nps.gov/index.htm National Park Service]
* [https://www.nps.gov/media/video/view.htm?id=10DA83B1-BEEF-4903-A80F-B6C4A8F50DA8 Official park film: ''Jewel Cave: Discovery in the Darkness'']
* {{Commons category-inline}}
* {{Wikivoyage inline}}
* {{OSM way|36337643}}

{{Protected areas of South Dakota}}
{{National Monuments of the United States}}
{{Black Hills, South Dakota}}
{{National Register of Historic Places in South Dakota}}
{{Subterranea}}

[[Category:Black Hills]]
[[Category:Caves of South Dakota]]
[[Category:Limestone caves]]
[[Category:Show caves in the United States]]
[[Category:National Park Service national monuments in South Dakota]]
[[Category:Civilian Conservation Corps in South Dakota]]
[[Category:Protected areas of Custer County, South Dakota]]
[[Category:Protected areas established in 1908]]
[[Category:1908 establishments in South Dakota]]
[[Category:National Register of Historic Places in Custer County, South Dakota]]
[[Category:Landforms of Custer County, South Dakota]]