National Park Service

U.S. Department of the Interior

Jewel Cave National Monument

South Dakota

For further information see http://www.nps.gov/jeca

Welcome!

For the past century Jewel Cave has been the 

center of science and world class discoveries. It is 

possibly the largest, longest, and most complex 

cave in the world. The geologic puzzles and 

spectacular passages hold many lifetimes of 

exploration. Although the cave extends hundreds 

of miles, the current explored area is only within a 

few square miles. 

Geology

Formed around 20-50 million years ago in the 

Mississippian Pahasapa (Madison) Limestone after 

the Black Hills uplift around 60 million years ago. 

Jewel Cave lies under a caprock of Pennsylvanian 

Minnelusa, which protects the cave from 

hydrologic erosion. Divided into distinct layers 

within the Madison, the cave cuts through paleofilled passages, chert, thick crystals, and dolomite.

Thermal and barometric changes in the cave are 

measured at points to extrapolate the volume of 

air flow based on weather changes. Current air 

flow research indicates that the total volume of 

the cave exceeds 7 billion cubic feet - only around 

2% has been discovered so far. 

Speleothems

The unique setting and speleogenesis of Jewel 

Cave results in many extraordinary speleothems. 

Calcite spar covers nearly every wall. Rare hydromagnesite balloons line passages and conulite 

baths rest gently in ancient chambers. 

Exploration

Cavers regularly explore the furthest reaches of 

the cave - primarily the southeast corner and the 

western end. Trips last between sixteen hours and 

four days. A survey camp was established to allow 

further exploration in the southeastern corner 

beyond the restricting Miseries. Through the help 

of organized volunteers and the Paha Sapa Grotto, 

Jewel Cave’s surveyed length increases a few miles 

a year.

Through cooperation with international universities, research institutions, and other federal agencies, Jewel Cave National Monument continues to 

pursue ground breaking research in karst science. 

Further research in the park includes an intensive 

geologic investigation into the faulting patterns 

and a paleontological flood study to correlate the 

role of large scale floods with the current speleogenetic model.

Contact Information

Jewel Cave National Monument

11149 US 16

Building B12

Custer, SD 57730

ph 605-673-2288

fax 605-673-8301

jeca_interpretation@nps.gov

Access

Three tours are available to the general public: a 

1/2 mile scenic tour, a 1/2 mile wild caving tour, 

and a 1/2 mile lantern tour. These tours allow 

people to see the great diversity of Jewel Cave. 

Jewel Cave’s trip leader program provides additional access to key spots in the cave and prepares 

people for exploration and survey trips. 

Jewel Cave

Cave Length 146.18 Miles

Cave Depth 632.53 feet

Years of Known Exploration 1900 - present

Visitors per Year ~100,000

-200000

-150000

-100000

-50000

0

50000

100000

150000

200000

-120000 -80000 -40000 0 40000 80000 120000

Scatterplot of calculated versus measured flow-rate data, Jewel Cave Historical

 Entrance, January 2005, 1 h means for cave volume = 400 million m3, KV = 30 hours

calculated air-flow rate(m3/h)

measured air-flow rate (m3/h)

NPS/DAN AUSTIN

NPS/DAN AUSTIN

NPS/DAN AUSTIN

NPS/MARC OHMS NPS

ANDREAS PFITSCH

NPS

NPS Caver next to frostwork at Rambling Loft

Top Right: 

Gypsum flowers along lip 

and breccia

Left: Thermal 

imaging of human temperature during 

lantern tour

Bottom Right: 

Water samples 

being collected at Big Duh

Far Right: 

Ultra-sonic 

anemometer 

measuring 

wind speed 

and volume in 

historic section 

of Jewel 

Top: Cavers travel through the loft section of Jewel Cave. Flagging tape marks 

special areas protected for their intrinsic value.

Bottom: The jewels of Jewel Cave, Dogtooth Spar calcite crystals, line many 

passages. 

NPS/DAN AUSTIN

NPS

NPS

Research

NPS

NPS

NPS/ART PALMER