Inner Space Cavern
Click on Map below for a larger image
- Location: Georgetown, Williamson County
- Length: 4,572 m (15,000 ft.)
- Depth: > 24 m (80 ft.)
- Hours: 9 a.m. to 6 p.m.
- Length of Tour: 1:15
- Admission: Please call for current rates.
- Phone: (512) 863-5545
- Other Amenities: Country store, candle
factory nearby. Downtown historical district 3 miles away.
- Author: William R. Elliott
Head north from Austin
on IH 35 for about 27 miles to Exit 289 onto Business 81 to Georgetown.
Turn left under the overpass and cross the railroad tracks on the west
side to the cave headquarters. The cave actually goes under the Interstate
Inner Space Cavern
is a large, complex cave with many beautiful formations and interesting
displays of Pleistocene-age mammal bones.
Known to paleontologists as Laubach
Cave, Inner Space was discovered in 1963 when boreholes were drilled to
test for a highway overpass on IH 35. A cavity was repeatedly found at
about 10 m (33 ft.), and a 36-inch corehole was drilled to investigate.
A highway engineer was lowered on the drill stem into what is now called
the "Outer Cathedral." The Highway Department soon allowed exploration
by the Texas Speleological Association, and about 2.1 km of passage were
mapped. The cave was sealed, and the freeway was completed.
In 1964 the Georgetown Corporation
was formed and leased the cave from the Laubach family, who retained the
right to use the cave. They soon excavated a sloping shaft into the west
side of the cave with the help of cavers. The cave was opened to the public
as a show cave in 1966. Visitors enter the cave on a cable car ride. The
trail, about 550 m (1,800 ft.) long, is smooth and sloping, admitting even
wheelchairs. At first the trail passes through trenches cut into the floor,
but soon it enters the large Outer Cathedral, where one can see the corehole
where the first explorer entered. A beautiful white flowstone, The Flowing
Stone of Time, can be seen with water flowing over its flanks. The tour
then passes under a high ceiling with large scallops and pendants, past
the talus cone of Bone Sink, where a crumbling mammoth tusk is visible,
to the Inner Cathedral. The tour then stops at the Lake of the Moon for
a dreamy sound-and-light show, then moves on to the Lunar Landscape, which
examines another side of the bone sink. The tour then retraces its route
to the entrance. A religious son et lumiere show is presented at
The Flowing Stone of Time.
Inner Space is a complex floodwater
maze superimposed on an ancient trunk passage system. The cave is generally
oriented north-south and consists of large passages and rooms interconnected
by smaller passages, the latter probably of more recent origin. The cave
occasionally floods with clear, phreatic waters, closing part of the trail
for months. "The Volcano" is an interesting feature in the off-trail area;
it is a mud crater about ½ m across in the corner of a room. The
Volcano probably was formed by water welling up out of the floor. A large,
plugged sink nearby could provide the necessary hydrostatic pressure after
a heavy rain.
Inner Space is one of the leading Pleistocene
paleontological sites in Texas. Several sinkhole entrances were open to
the surface about 13,000 to 25,000 years ago, as evidenced by dated remains
of extinct mammoth, saber-toothed cat, glyptodont (a Volkswagen-sized armadillo),
camel, horse, ground sloth, short-faced bear, peccary, bat, and other species.
The oldest radiocarbon-dated bone from a Texas cave came from Inner Space
± 490 years before present. The cave contained several complete
skeletons of Platygonus compressus, an extinct peccary. This species
had a habit of crawling into remote passageways to die.
Exploration is not complete but has
been slowed by breakdown areas that are difficult to excavate. A resurvey
of the cave seems to have bogged down.
The cave contains a diverse invertebrate
fauna, including two endangered species, Texella reyesi (Bone Cave
harvestman) and Batrisodes texanus (Coffin Cave mold beetle).
Elliott, W. R. 1970. Inner Space Cavern-Third
longest cave in Texas. Texas Caver, 15:203-211.
Elliott, W. R., and L. O'Donnell. 1993.
Draft recovery plan for endangered karst invertebrates in Travis and Williamson
counties, Texas. U.S. Fish & Wildlife Service, Albuquerque, New Mexico.
Kastning, E. H., Jr. 1983. Geomorphology
and hydrogeology of the Edwards Plateau karst, central Texas. Ph.D. dissertation,
Univ. Texas, Austin, xxxi + 656 pp. + 6 pl.
Reddell, J. R., and W. R. Elliott.
1991. Distribution of endangered karst invertebrates in the Georgetown
area, Williamson County, Texas. Report to City of Georgetown. 64 pp.
Russell, W. H. 1980. Inner Space: Exploration
of the dry section. Texas Caver, 25:101-103.