Minnetonka Cave #1
William H. Mullins
Mammoth Cave
John W. Bova
Minnetonka Cave
William H. Mullins
Natural Bridge Caverns, San Antonio, Tx #19
Millard H. Sharp
Cenote Of Dzitnup
J. Gerard Sidaner
Natural Bridge Caverns, San Antonio, Tx #28
Millard H. Sharp
Seven Star Cave, China
George Holton
Longfellows Lake, Carlsbad Caverns
Bruce Roberts
Natural Bridge Caverns, San Antonio, Tx #1
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #2
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #14
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #24
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #26
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #31
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #39
Millard H. Sharp
Lehman Caves #1
Richard W Brooks
Natural Bridge Caverns, San Antonio, Tx #15
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #17
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #32
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #18
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #35
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #36
Millard H. Sharp
Twin Domes, Carlsbad Caverns
Tracy Knauer
Stalactites & Stalagmites
Spencer Sutton
Stalactites & Stalagmites #1
Spencer Sutton
Natural Bridge Caverns, San Antonio, Tx
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #4
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #6
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #8
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #9
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #16
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #20
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #22
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #27
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #29
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #34
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #38
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #40
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #41
Millard H. Sharp
Mitchell Caverns
Richard W Brooks
Lehman Caves
Richard W Brooks
Florida Caverns State Park #10
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #3
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #7
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #21
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #23
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #30
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #33
Millard H. Sharp
Seven Star Cave, China #1
George Holton
Natural Bridge Caverns, San Antonio, Tx #11
Millard H. Sharp
Stalactites & Stalagmites #2
Spencer Sutton
Natural Bridge Caverns, San Antonio, Tx #5
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #10
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #25
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #37
Millard H. Sharp
Reed Flute Cave, China
George Holton
Dau Go Cave, Vietnam
Nigel Cattlin
Natural Bridge Caverns, San Antonio, Tx #12
Millard H. Sharp
Natural Bridge Caverns, San Antonio, Tx #13
Millard H. Sharp