Wind Cave National Park - Wind Cave Radio Survey (U.S. National Park Service)

NPS Photo by Jim Pisarowicz

Caver in a Crawlway with Cave Radio Antenna

In June of 1984, electrical engineer and amateur radio enthusiast Frank Reid attended the National Cave Rescue Commission seminar held at Wind Cave National Park. After an intensive one-week training session he left, vowing to return with his equipment and expertise. In January of the following year, plans were made for Wind Cave to have its first complete radio survey.

NPS Photo by Jim Pisarowicz

Ranger Dennis Shreves Carrys Cave Radio Antenna Through Wind Cave

The word "radio" is actually misleading. The equipment used was not the type of radio with which most people are familiar. Generating conventional radio waves with the power to penetrate more than a hundred feet of rock would require prohibitively large antennas. The device used at Wind Cave, designed and constructed by Frank Reid, made use of what is known as magnetic induction. The transmitter, which required two people to carry, was taken to the desired cave location by cavers. When activated, it generated a magnetic field which was detectable on the surface with the use of a special receiver. By utilizing the known properties of magnetic fields, it was possible to pinpoint the area on the surface which was directly over the transmitter. Carefully measuring the vertical angle of the field as it emerged from the ground allowed Frank to give an accurate estimate of depth. In all, 25 rooms from throughout the cave were located.

NPS Photo by Jim Pisarowicz

Ranger Dave Shafer Levels the Cave Radio in Wind Cave

The radio survey of Wind Cave answered many questions. It helped us understand exactly where many parts of the cave were located in relation to surface features and developments. It also helped us determine the depth of these areas. But most importantly, it will help the park produce a more accurate map of the cave. A careful surface survey between many of the location sites was performed by Dennis Shreves and several of his students at Kansas Tech during the spring of 1986. The data from this project eventually answered such questions as: "Is the large room north of the Club Room (know as Club Room II or Club Room North) really offset from the Club Room as the map shows?" and "How close are we to a connection in the Disappointment Chamber area?" It appears the map was inaccurate in both of these areas.
In order to assure that the surface locations would not be lost in the future, permanent monuments were constructed over each site. Brass caps, set in concrete, have the room name and other vital information stenciled onto them. Small, brightly colored stakes have been placed on each site to ease location. Visiting these sites is sure to increase your knowledge and appreciation of Wind Cave.

NPS Photo by Jim Pisarowicz

Frank Reid Finding Surface Location With a Cave Radio

Cave Room Name	Depth Below Surface in Feet (meters)
Calcite Lake	414.00 (126.28)
Chamber of Lost Souls	62.95 (19.19)
Chimera Room	198.10 (60.38)
Club Room	165.00 (50.29)
Club Room North	139.75 (42.60)
Disappointment Chamber (near)	172.98 (52.72)
Disappointment Chamber (far)	137.10 (41.79)
Elephant Trunk	340.10 (103.66)
Fairgrounds	188.80 (57.55)
Fairy Palace	69.45 (21.17)
Figure Eight Room	195.40 (59.56)
Garden of Eden	147.80 (45.05)
Gateway Hall	296.50 (90.37)
Methodist Church	142.40 (43.40)
Omnibus Hall	99.40 (30.30)
Pearly Gates	274.40 (83.64)
Plummer's Pit	264.28 (80.55)
Post Office	155.30 (47.34)
Rainbow Falls	84.20 (25.66)
Rookery	132.40 (40.36)
Second Crossroads	231.70 (70.62)
Selenite Avenue	246.03 (74.99)
Silent Lake	141.55 (43.14)
Windy City Lake	500.00 (152.40)
Xerox Room	214.30 (65.32)