Wind Cave - Fast Facts

National Significance Most boxwork of any known cave, most complex 3D rectilinear maze cave (network maze), seventh longest cave in the world, one of the most diverse mineralogical and speleothem assemblages and one of the largest barometric wind caves in the United States.
Rock Formation Madison (deposited during the Mississippian, 340-330 million years ago - locally called Pahasapa limestone), 275-325 feet (84-99 m) thick in the park.
Dip of Madison Formation Beds dip 4-5.5° to S 50° E.
Strike of Cave The cave strikes at N 52° E.
Cave Boundaries Cave is within a 1.1 by 1.3 mile rectangle (370.4 ha) on the surface.
Length of Surveyed Cave 143.16 miles (230.39 kilometers) as of November 2014.
Deepest Point Surveyed The Lakes are 654 feet (199.3 m) below the highest point in the cave.
Maximum Relief at One Point ~250 feet (76.2 m) through multiple levels near the south end of Half Mile Hall.
Elevations Natural Entrance 4084 feet (1244.8 m), Elevator Building 4059 feet (1237.2 m), Garden of Eden level 3940 feet (1200.9 m), Assembly Room level 3863 feet (1177.4 m).
Paleokarst Original caves and sinkholes (karst) developed in Mississippian times (320-310 million years ago) in a fresh/salt water mixing zone. Filled with Minnelusa sediments (red sand, silt, clay, and fragments of limestone, sandstone or chert) during Pennsylvanian times (310 million years ago). Deepest penetration seen in the cave is the upper-middle level at the Beauty Parlor, ~150 feet (46 m) of vertical relief.
Major Cave Development Probably during Paleocene-Eocene times (40-50 million years ago), definitely after Laramide uplift of Black Hills (60-70 million years ago). Cave developed along gypsum deposits and paleokarst zones.
Upper Level of Cave 80-130 feet (24.3-39.6 m) thick. It is near the chert layer and is characterized by smooth rounded walls and ceilings and domes, boxwork is rare, paleofill common, corrosion residue and fossils common.
Middle Level of Cave 100-120 feet (30.4-36.5 m) thick and divided into three sublevels. It is below the chert layers and is characterized by boxwork, wide and irregular passages, frostwork, and bedded limestone. Upper middle has nodules of chert, poor boxwork, crumbly bedrock, zebra rock, spar-filled vugs, and fossils. The middle has very well developed boxwork, lots of moonmilk, chert is rare, and low wide passages. Lower middle has a <¼ inch (6 mm) coating on everything with hard hollow floors.
Lower Level Cave 65-100 feet (19.8-30.4 m) thick. Characterized by canyon or fissure passages with thick coatings on everything, also with false floors and large vugs.
Cave Sediment Dating 0.9-2 million years based on paleomagnetic dating in a 30 foot section of loose, bedded sediments exposed at Selenite Avenue.
Draining of Cave Water stagnant from 40 million to 0.5 million years ago. Cave started draining as a backwater around 470,000 years before present (based on crust dating). Drained down to Boxwork Chimney 250,000 years ago, draining at a rate of 1.3 feet (.4 m)/1000 years. Began draining from base of Boxwork Chimney by 155,000±18,000 years ago. Lakes were 60 feet above current level 1,500 years ago (based on calcite raft dating).
Water Flow into Walk-in Entrance 1-2 feet (.3-.6 m) deep from a May 19, 1982 rainfall event. It ponded at the low spot between the North Room and the first transformer.
Presence of Water 11% of survey stations have some form of water nearby, mostly under surface drainages.
Running Water What the Hell Pool started running in 1996 and Rebel River, both in the Lakes section.
Large Lakes Phantom (McDonald's Wind River?), and Windy City Lake (Calcite, Transition, Jim-Bob's Plunge and Lovely Little Lake have merged with the rising water table and Windy City Lake to form one large lake).
Elevation of Lakes 3630 feet (1106.4 m).
Losing Streams in Park Beaver and Highland Creek average a combined loss of 2,514,240 gallons (9,554,112 liters) per day.
Lake pH and Temperature pH is 7.7-8.35, while temperature is 56.7-57.2° F (13.7-14.0° C).
Cave Lake Water Local artesian water that has cooled and degassed in the cave. Saturated in terms of calcite.
Dye Traces Various traces ranged from 6 hours (south end of parking lots to Minnehaha Falls), to 2 months (picnic ground to Minnehaha Falls), to 1½ years (south end of parking lot to Assembly Room), to a long trace of 4½ years (gully SW of parking lot to Pop Secret).
Types of Cave Minerals Calcite, aragonite, hydromagnesite, gypsum, selentie, magnesite, quartz, manganese oxides, hematite, geothite, huntite, mirabalite, romanichite, ice.
Cave Sediment (Minerals/Rocks) Quartz, calcite, mica, feldspar, tourmaline, hematite, gypsum, hornblende, quartzite, arsenic, illite, kaolinite chlorite, Deadwood siltstone, Minnelusa shale, precambrian schist.
Flowstone/Dripstone Distribution 5% of survey stations have flowstone or dripstone near them. Of these, 83% are in the upper level.
Wall Crusts Subaqueous deposits 2-3 cm thick in lower levels. Deposited as waters receded.
Unusual Formations Boxwork, helictite bushes, quartz rinds, logomites, hydromagnesite ballons, dogtooth and nailhead spar, quartz, christmas trees, button popcorn, sawtooth flowstone, gypsum luster, flowers, starbursts, and hair and conulites.
Biggest Earthquakes Heard January 27, 1990 - 3.9 Richter scale, heard but not felt in the cave, 10 second rumble. August 6, 1999 - 3.0 Richter scale, heard for 3-5 seconds but not felt in the cave, rolling thunder-like sound.
Cave Volume of Surveyed Passage 39,110,000 ft³ (1,107,467 m³) (based on a average passage size, 2% of Conn's total volume estimate).
Volume of All Cave Herb Conn estimated total cave volume of 2 billion ft³ (55 million m³) based on airflow.
Barometric Winds >75 mph (120 kph) is highest recorded measurement at Walk-In Entrance before revolving door was installed. The highest recorded measurement at the Natural Entance was 25 mph (40 kph). North Room 0.28-1.75 mph (.5-2.8 kph) (March-August 1985).
Air Exchange Average of 1,000,000 ft³ (28317 m³) of air from cave exchanged with the surface each hour.
Effects of Air Exchange Warm summer air cools and water condenses on walls. Cool, dry winter air warms up and evaporates water. When the cave is expelling, 16.1 gallons (73.2 liters) of water is lost per hour out the natural entrance.
Temperature 53° F (11.7° C). Varied 12° F from entrance to Post Office before revolving door. Mean annual surface temperature is 47° F (8.3° C) for the area. It is theorized that the cave is heated from below by geothermal gradient.
Radon 0.23 working levels, average between May and August. Varies between 0.27 and 0.34 between October and November.
Faunal Remains Bison, elk, frog, woodrat and bat from Chamber of Lost Souls - undated remains. Bat and woodrat bones found scattered around the cave.
Biota (near entrances) Bats, bushy-tail woodrats, deer mice, tiger salamanders, frogs, rattlesnake, bullsnake, milksnake, earthworms, camel crickets, beetles, spiders, ant lions, flies, springtails, nematodes, mites, microbes, fungi (12 genera), protozoa and bacteria.
Dark Zone Cave Biota (near trails) Nematodes, springtails, mites, microbes, bacteria and fungi.
Dark Zone Cave Biota (far from trails) Springtails, mites, protozoa, bacteria, and fungi.
Bat Species Myotis ciliolabrium (small-footed myotis), Eptesicus fucus (big brown); Myotis volan (long-legged), Myotis lucifugus (little brown), Myotis subulatus (small-footed), Myotis thysanodes (fringed-from Coyote Cave), Corynorhinus townsendii (Townsend's big-eared).
Cave Adapted Species Springtails (collembolas, Arrhopalites caecus and Onchopodura curveseta).

Last updated: January 23, 2018

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