Spring Valley Caverns

 

Bat River Cave

Bat River Cave, located in S.E. Minnesota, is home to the largest concentration of roosting bats (in any natural cave) in the Upper Midwest. The original portion of this cave has been known to exist since pre settlement times. However, in 2007 John Preston, outfitted with SCUBA gear, dove through a water filled sump at the end of the cave and discovered a huge room with a tremendous waterfall crashing down into it. He reported that the cave continued ahead, and shortly thereafter John Ackerman and Phil Gemuenden followed Preston through the sump and explored over one mile of spacious decorated passages lined with bats. A safe man made entrance has now been created to further exploration and scientific studies. To date, 2.84 miles of cave passages have been explored.

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Read the HISTORY

   

Natureal Cave Entrance
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The natural spring entrance.

Tim Stenerson, John Preston and John Ackerman prepare to
enter the cave to dive the sump.
Discovery Trip
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Disvered New Section
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This is where we surfaced into the new cave after groping our way through a 50’ long passage that was icy cold, pitch black and constrictive.
Tami Thomsen, John Ackerman, Dave Wysocki, Dan Pertzborn prepare to enter the original cave entrance.
When Tami and John arrived at the sump they transported specialized radio gear through the water filled passage so they could pinpoint a suitable man made entrance in the newly discovered spacious cave.
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Passing through low airspace.
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Possible entrance site.
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Once through the sump Tami and John remove their diving gear and make their way through almost one mile of spacious newly discovered cave passages. Here Tami sends low frequency radio pulses to the surface, where they are successfully received by Clay Kraus and Charles Graling.

A stake is placed at the precise location above the in-cave transmitter. This exact spot marks the future man made entrance.

New entry site.
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Drilling test hole.
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Ready to drill a test hole to verify the accuracy of the cave radio readings.
A camera is lowered into the cave to verify the exact proposed entrance location.
Success! The main cave passage is clearly visible 65 feet below the surface.
Looking into cave.
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Drilling to install case.
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A specialty rig prepares to remove dirt and loose rock until solid bedrock is reached.
Steel casing was then installed on top of the bedrock.
Installing Casing
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Drilling Main Hole
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A customized drilling machine is positioned over the casing and bores the main 30” diameter shaft down to the cave ceiling, which is 57’ below the surface.
John returns from his first trip down the newly created entrance.
First person down.
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Instaling Ladders
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After the ladder sections were installed a secure steel lid was attached. Final grading and planting of native grasses have completed the project.

--- Underground ---


TNew entrance site.
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New entrance site.
Looking up from the cave.
65' Entry
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Notice Bats on wall.
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We are not the only visitors to the cave.
We found over two miles of breathtaking passages with a mixture of textures and colors.
Textures and Colors
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Virgin passage
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On the way to the waterfalls.

Some of the passages are 25ft tall.
Inside Cave
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Prestons Room
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The water temperature is 48 degrees. Without special wetsuits to keep cavers warm they would soon succumb to hypothermia.

Jim Edberg and Clay Kraus amongst draperies and other unique formations.
Unique Formations
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Inside Cave
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This is an incredible cave system.

Ttraveling along the main passage.
Unique Formations
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Rare Formations
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Ancient rare formations .

The water that flows through this cave system creates many natural pools, dams and waterfalls.
Rimstone Dam
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Flying Bat
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This cave system contains the largest hibernating bat colony in any natural cave in the Tri-State area. Over 4000 bats return to Bat River Cave each fall to seek shelter and safety.
Read the STORY
Erin Meyer (adjacent neighbor) descends a waterfall which cascades into a large room.
Waterfall
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The normal water flow is typically low and calm, as shown on this photo displayed above.TNew entrance site. A steady rain had fallen during the day on August 18, 2007, which presented a perfect opportunity to witness the effects on the cave. Three cavers entered the cave with the intention of traveling only a short distance along the main route. During that time period a sudden intense cloud burst occurred and a violent water surge raged through the cave, almost carrying the cavers to their deaths.

 

3:43 p.m.
Jim enters the cave. Note that the water level has risen.
Rising Water
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Ceiling Shower
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4:03 p.m.
We encounter a fantastic waterfall where only a dry ceiling existed before.


4:17 p.m.
The water begins to rise and becomes turbulent. Even though the main passage is spacious we decide to abort the tour.
Becoming more Turbulant
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Current getting stronger.
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4:22 p.m.
We round a bend and struggle against the current to retreat.



4:40 p.m.
Panic sets in as we loose our footing against the incredible force of the water surge.

Violent surge.
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Safe at ladder.
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4:59 p.m.
Seconds after this photo was taken it was almost impossible to stand in the passage without getting swept away.




--- Bone Discoveries ---


Streambank
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In 2008-9 over 175 rare bones dating back to the ice age were discovered along some of the stream banks in Bat River Cave and nearby Tyson Spring Cave. Read the account




The artifacts are now being analyzed by the Illinois State Museum and are being compared to the incredible finds in nearby Tyson Spring Cave.

Being analyzed
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Pleistocene bones
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Some of the bones are from the Pleistocene era and are rare specimens.




Thought to be the upper right jaw of an extinct bison. Tests are ongoing.
Extinct bison
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Ice age bones
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Over 175 bones have now been collected in Bat River Cave and nearby Tyson Spring Cave, resulting in the most significant scientific discovery in any Upper Midwest cave.




--- Continued Exploration ---



Multiple exploration trips were conducted upstream from the new entrance. After sliding on our stomachs for 1,800 feet (through 48 degree water in low air spaces) the ceiling abruptly rose to 30' and we found ourselves exploring a huge cave segment. Eventually the ceiling height diminished, and John Ackerman moved ahead for several hours with only inches of air space. Amazingly, the ceiling once again rose suddenly to over 60 feet, and another large cave segment was discovered! The cave length is now 2.84 miles as exploration continues..

Breaking Through
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Huge Breakdown Rocks
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If these huge breakdown rocks would have fallen completely to the floor they would have blocked the passage and we never would have discovered the rest of the cave.

New discovery section. Very strange wall patterns visible on the right wall.
New Discovery Section
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Free Hanging Formation
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Joe Myre inspects a free hanging formation. At one time this formation was formed on top of a mud bank. Later the mud bank was washed away, leaving the formation suspended.

Another example of a suspended formation.
Suspended Formation
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Bizarre Floor
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We were amazed at this bizarre looking floor.

As time progresses water is eroding the meandering passages deeper and deeper.
Eroding Passages
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Bat River Cave History
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