Spring Valley Caverns


Minnesota Cave Preserve Exploration History Timeline

Spring Valley Caverns
Cold Water Cave
Goliath's Cave
Tyson Spring Cave
Bat River Cave
Holy Grail Cave

Spring Valley Caverns

1966
(May)

John Latcham purchases the 470-acre farm on a Contract for Deed from Ammon Grems. This 27-year old farmer discovers what he surmises is a newly opened sinkhole while searching for a lost calf while on horseback. (Based on a May 1966 photo of this sinkhole, which shows moss and lichen on the entry rock, a high possibility exists that the cave had been accessible to human visitation for many years. In fact, the Grem’s family later stated that they had always been aware of the caves existence but simply acknowledged it as another creation of the natural wilderness.)

Cave specialist Ron Spong is summoned, and together with a team he assembles, proceeds to explore and map the cave.

1967

This cave system is documented to be one of the most spectacular in the Upper Midwest, and John subsequently decides to commercialize it. Together with his new partner, Roger Winters, the two begin the arduous process. Large slabs and rocks are broken up, the passage floors are leveled and spread with gravel, electricity is brought to the site and wooden stairways are constructed.

1968
(Mar)

A WWII Quonset building is placed over the cave entrance, brochures are printed, tour guides are hired and tourists begin arriving.

1969

Subcontractors place liens on the building and improvements and the fee owner forecloses on the Contract for Deed, forcing the young farmer and his partner to go bankrupt. Grems repossess the farm and that December sells it to Joseph Miliner on a Contract for Deed. Joe continues the commercial operation but soon shuts it down and boards up the building.

1975

Miliner assigns the Contract to Deed to Ilert Eilders.  No caving is permitted.

1981
(Dec)

Miliner pays off the Contract for Deed from Grems.

1983

Eilders assigns his Contract for Deed to James Manggaard.  The Minnesota Speleogical Survey (MSS) visits Jim and is allowed access to the property.

1984
to
1987

The MSS officially surveys Spring Valley Caverns.  Dave Gerboth, an MSS member, takes special interest in this cave.

1987

John Ackerman, a cave explorer from the Twin Cities, gets acquainted by Dave Gerboth.  John and Dave discover numerous caves on this farm in some of the 35-40 sinkholes.

1988

1988 Twice vandals break through the flimsy gate and damage formations in Spring Valley Caverns. The MSS removes rotting wood and dilapidated wiring that was installed in the cave during the commercialization attempt. John Ackerman was busy with other projects on the Manggaard farm but finally tours Spring Valley Caverns for the first time.

1989 (Dec)

Manggaard decides to sell the farm, and after lengthy negotiations, John Ackerman purchases roughly one half of the farm and acquires underground cave rights to the other half.   Manggaard then sells both homes on the property along with 10 acres each and pays off the Contract for Deed with Miliner.

1990
(Apr)

Using explosives, John and Dave widen a long narrow crevice at a "dead end" within Spring Valley Caverns.  After many months of grueling effort, they make a breakthrough to find a spectacular system of interconnecting passages.

1991
(Apr)

John needed an adjoining 10 acres to create an entrance into the newly discovered remote area in Spring Valley Caverns called SVC IV, but Mr. Manggaard would only sell a minimum of 70 acres.  John purchases 70 acres and sells 60 acres to a young farmer named Matt Snyder on a Contract for Deed.

1991
(Jun)

John purchases an additional acre from his new neighbor to create a back door into the newly discovered river section of Spring Valley Caverns called SVC III.  This farmer, Rick Christianson, had recently bought the other half of the Manggaard farm.  An easement was provided from this new parcel back to the Cave Farm.

1991
to
1997

More caves on the property are discovered and Spring Valley Caverns now stretches almost 5 1/2 miles in length.  John and Dave decide that in addition to exploration, preservation is a key priority.  John takes legal steps to assure the property and all caves will be permanently protected after his death.  It is decided to designate the property as a Cave Preserve.

1997

The Quonset building is demolished and excavation begins in preparation for the new building over the main entrance to the caverns.

1998

The unique building was finally completed in late fall and allows large groups of nature enthusiasts a place to gather before and after entering the caverns.

1999

John purchases a 10 acre parcel from his neighbor which contains an important and rare karst feature called a Blind Valley.  This property is annexed to the Cave Preserve with an easement.  It is thought that Spring Valley Caverns extends beyond this parcel and could be accessed through one of several sink holes located within this property.

2000

John repurchases the 60 acres he originally sold Snyder in 1991 for four times the selling price.  This property, which lies above Spring Valley Caverns, is mostly tillable but contains a 14 acre hardwood forest that gently sweeps down to Bear Creek with its spectacular limestone bluffs.  The picturesque entrance to "Bear Den Cave" is located high on one of these bluff faces.

This same year John purchases another adjoining farm which increases the Cave Preserve to 325 acres  (over a full 1/2 section of land).

2004

After 3 years of negotiations John purchases an additional 160 acres of land adjacent to the Cave Farm, formerly known as the King Farm. This scenic property encompasses hardwood forests, open meadows and towering limestone bluffs. Deer Creek is a prominent feature with its adjacent towering limestone bluffs. The Minnesota Cave Preserve's land holdings are approaching 500 acres.

2010
(Mar)

John purchases 76.5 acres adjoining the property he acquired in 2004. This property also encompasses hardwood forests, open meadows and towering limestone bluffs on both sides of Deer Creek.

2012
(Sept)

John purchases a 24.3 acre farm bordering the eastern boundary of the Cave Farm. The Cave Farm will now have an access from another county road. The only sinkhole on the property was excavated and a cave was discovered!

The Cave Farm portion of the Minnesota Cave Preserve now consists of 585.8 acres, combined with 192 additional underground rights involving a total of 36 caves.

See the photo HISTORY

Cold Water Cave
1967

The cave system, located just south of the Minnesota border, in northern Iowa, was discovered in 1967 by several cavers who dove under the frigid water that flows out of a magnificent cliff face in the Coldwater Spring State Preserve. Shortly thereafter, the State of Iowa took exclusive control of the cave and created an artificial entrance into the cave on private land which they leased.

1975

In 1975, after failing in their attempt to secure funding for commercialization, the artificial 94 foot deep shaft reverted back to the landowners.  Since an underwater gate was installed at the natural spring discovery passage in 1970, the only access to the cave since then has been through the 94 foot shaft.

2002

Due to access restrictions, John Ackerman began a quest during the mid 1990's to create a second artificial entrance to this National Natural Landmark cavern system.  In 2002 his unwavering efforts started to become a reality when he was successful in convincing a landowner above the cave to sell 5 surface acres, along with 200 underground rights to the system.  A law firm was immediately retained and helped pave the way for John to proceed with his plans.

2003

The Midwest's oldest and largest well drilling firm, Thein Well Co., was contracted to drill a 30 inch diameter, 188 foot deep shaft into the cave.  This project was initiated during 2 bitterly cold winter months in the winter of 2003 and was successful even though there were numerous mechanical breakdowns due to the incredibly tough limestone.

Shortly before the drilling project was started, a long forgotten pioneer cemetery was discovered within feet of the new shaft site.  In addition, numerous glitches were discovered during the abstract search.   But eventually, in December 2003, the law firm completed the arduous task of ironing out all the problems.

2004
(May)

The shaft lid and ladders were complete and the project was formally proclaimed a huge success.

2006
(Dec)

John Ackerman and Clay Kraus discover new passages deep into the cave system. Ackerman noses his way through low air space until the passage height increases, and then goes on to discover several tall domes, one with a fantastic waterfall dropping from the top. READ THE STORY

See the photo HISTORY

Goliath's Cave
1950's In the mid 1950’s, cavers from S.E. Minnesota report that they have discovered a significant cave in a sinkhole near Cherry Grove. Shortly thereafter the entrance became blocked by a massive talus pile.
1955 - 1980 During the next 20 years cave explorers, including Ron Spong, a charter member of the Minnesota Speleological Survey, would occasionally attempt to remove enough of the talus pile to gain entry into the cave.
1980 A seven inch rain event was responsible for moving and redepositing loose rock and soil at the entrance. Ron managed to access the cave, and after negotiating his way through the 2 near-sumps, located just inside the cave, he hiked through the upper level of the cave before retreating due to another immanent flood threat.
1984
(Feb)
Jim Magnusson, the president of the Minnesota Speleogical Survey at the time, removes rocks and mud from the sinkhole entrance. He explores and surveys the extensive upper level cave. Subsequent trips into the cave reveal that the twin dips in the entry passage are filled with water most of the time, making access to the main cave impossible until the water gradually resides.
1985
Jim Magnuson, Mike Lilja and Dave Madsen forge their way through the near sumps, travel through the upper level and drop down to the lower stream passage. They discover then entire lower level, all the way to the 15' falls. After scaling the falls they find that the incredibly tall main passage abruptly drops down to a flat, wide and very low passage. With a very limited air space available, Madsen and Lilja slide ahead for several hundred feet before retreating. They report that the passage continues ahead.
1986
(Jan)
Steve Porter, Larry Laine and Dave Gerboth survey the lower level to the waterfall. Steve picks up where Mike Lilja and Dave Madsen left off and moved forward approx. 400 feet before turning back. Extremely low air spaces were reported, interrupted by periodic tall domes along the way.
1986
(Mar)
Jim begins to excavate a man-made entrance so that access will be available year round. A site is chosen beyond the dips and digging starts both above ground and within the cave. A pneumatic pump is occasionally used to lower the water in the sumps so work can continue.
1986
(May)
A small shack is constructed in the woods in close proximity to the work site to make weekend trips bearable. Six feet down solid bedrock is encountered and subsequently a 150-pound gasoline water pump is brought into the cave to quickly lower the sumps so the error can be identified. Mike Lilja is overcome by the noxious fumes, looses consciousness and falls face first into the water while Greg Heideman struggles to exit the cave. Neighbor Steve Landsteiner is summoned and arrives with an oxygen tank. With Jim’s help they attempt to feed oxygen into Mike’s lungs and haul him out of the cave using a makeshift Indian traverse. Mike is brought to a hospital in Cresco, Iowa but since there was water in his lungs and his core temperature was 81 degrees he was airlifted by Mayo One to St. Mary’s Hospital in Rochester where he made a complete recovery.
1986
(Sept)
John Ackerman, Dave Gerboth and Kent Parker visit with Jim at the cave site. John is thoroughly impressed with the project
1986
(Dec)
A cave radio is taken into the cave to determine where the second shaft could be created
1987
(Jan)
It is estimated that the cave is positioned approximately 24-27 feet below the surface. Work on the second entrance commences in January and continues throughout the winter and into the spring. The task is arduous due to the inclement weather and clay composition, but spirits remain high.
1988
(Spring)
Just as the 21-foot level was reached, the owner of the cave, Thomas Kapper, notifies Jim that due to liability concerns he is no longer welcome on the property.
1998
(Dec)
Kapper’s seek a conditional use permit to quarry away the cave and surrounding woods. Local neighbors attend a Board meeting and voice their concerns against the proposed permit. The DNR expresses concern about the obvious contamination of the stream that flows through the cave and out into Forestville State Park property.
1999
(Dec)
A division of the DNR, the SNA (Scientific Natural Area) purchases the site from Kapper’s and promptly gates the cave. A meeting between cavers/scientists and the SNA is held where it is learned that access rights are a low priority to the SNA. Signs are posted around the perimeter of the property warning that it is illegal for anyone to enter the property with any caving gear.
2004
(Spring)
Citing unwarranted bureaucratic control, cavers rally to remedy the situation and contact adjacent property owner Venita Sikkink. A significant portion of the Goliath's Cave system lies under her 360 acre farm. Numerous meetings are held where options are discussed.
2004
(Fall)
The entire Sikkink family supports the cause and sells John Ackerman several surface acres including 358 acres of underground rights to Goliath’s Cave. John creates a 75-foot deep access shaft into the cave and allows access to cavers and scientists once again.
2005
(Winter)

Dave Gerboth, Clay Kraus and John Ackerman systematically scour the cave for unknown passages and select potential sites. After removing sediment from three sites, they squirm through the constrictions to find fantastic major cave segments.

2005
(Feb)

John Ackerman and Clay Kraus venture deep into the unsurveyed lower level portion of Goliath's Cave and use a special cave radio to determine their position as it corresponds to the surface approximately 150 feet above them. After precise calculations are compiled it is discovered that the Sikkink home lies directly above the largest body of water in the cave. This revelation was astonishing since the 135 year old Sikkink home lies well over one mile away from the cave entrance and is nestled in a secluded wooded cove.

Ackerman also discovers a 20’ tall dome room just off the main stream passage. He identifies a gap near the ceiling and feels it could be enterable with the right gear.

2005
(Spring)

A sudden snow melt inundated the DNR/SNA natural entrance with a torrential river of water and temporarily blocked the entrance with tons of rocks.

2005
(Summer)

Several surface acres surrounding David’s Entrance are planted with natural prairie grasses and forbes.

2005
(Nov)

John Preston and John Ackerman don SCUBA gear and penetrate a water filled sump, which leads them into a fantastic new dry segment of Goliath’s Cave. One month earlier John Preston had groped his way through these same unexplored frigid water filled passages, which led him into this new section. He scouted a short distance ahead before returning with the incredible news. Four weeks later, outfitted with survey and life support gear, John Preston and John Ackerman make the dangerous trip through these jet-black subterranean passages and explore the new section. They return after surveying one-third mile of large pristine cave passages, which are highly decorated with a variety of formations. This amazing discovery is rated as one of the all time greatest finds that involved underwater exploration in this state. Click to read the entire acccount.

2006
(Mar)

Armed with a grappling hook, John and Clay returned to the dome that John discovered in the downstream section in 2005. John manages to lodge the grappling hook into the void and climbs up. John and Clay are astonished to discover a 42’ tall room with a 6’ tall passage leading off into the distance. After 52’ the passage is blocked by large rocks. They do not have a rock hammer.

2008
(Feb)

John, Clay, Charles Graling and Dave Gerboth return to Grappling Dome with a rock hammer. John and Clay climb up to the room, travel along the passage to the rock blockage and after three hours successfully break the large offending rock. They move forward, past the previous rock choke and are stunned at what they walk into. A large dry upper level thoroughfare passage was discovered. John and Clay explored and surveyed this borehole passage for ¼ mile before retreating. Read Story

2008
(Mar)

John pushes through a tight passage near the end of the newly discovered upper level and discovers a deep pit. He installs a cable ladder at the top and climbs down the narrow crevice. He finds himself in the main stream passage but cannot forge ahead because he is not wearing a wetsuit. John barely manages to get back up to the upper level due to the offset nature of the drop.

2009
(Jan)

Cave diver Tami Thomsen, assisted by John Ackerman, resumes exploration at the downstream sump that has stopped cavers since the beginning. Along the way Tami makes voice contact with the upper level, where Clay Kraus is positioned. She continues to follow the stream passage over 700 feet until her progress is halted due to a major collapse. (Directly under the Canfield Creek.) One week later both John and Tami retrace her discovery route. John thoroughly inspects the sump but is unsuccessful at locating any air gaps which may allow access behind the sump. On the way back John began to remove rock and sediment in a promising dig at the base of a dome room. (Later pushed, but only discovered about 30')
Since the water in this stream passage has been traced to Forestville State Park, it is estimated that a huge cave system awaits discovery along this subterranean route. At this time it is highly doubtful that a connection can be made through the Goliath's Cave system unless the large terminal sump opens up, allowing us access to the remaining stream passage
.

2009

Adventure writer Cary Griffith recounts the riveting story of how cave explorer John Ackerman created David's entrance into Goliaths Cave, effectively circumventing government control of the cave.

2013

A final map is produced of the cave . The total length to date is 2.39 miles. View the MAP

See the photo HISTORY

Tyson Spring Cave
Pre 1862 No doubt Native Indians utilized the cave resurgence as an important year round water source. Since the limestone bluffs and wooded setting is so picturesque it is thought that this special place was revered.
1862 The tract of land, which contains the cave resurgence, is gifted to a war widow from the U.S. government. [War of 1812]. Since land was plentiful at the time it was customary for the Government to deed land to disabled veterans and widows of military personnel.
1868 The war widow assigns the tract to Mr. Harper Tyson.
Late 1870's A professional photographer from the nearby town of Chatfield transports heavy gear to the remote site of the cave resurgence and takes a stereoview photo of the idyllic setting.
1930's Local inhabitants took great joy in venturing into the cave in wooden boats. After 900 feet they were abruptly stopped where the ceiling sloped down to meet the water. (Referred to as a sump).
1960's - 1970's Ron Spong, a charter member of the Minnesota Speleological Survey (MSS), leads an effort to penetrate the sump in hopes of finding a continuation of the cave. He determines that the water filled passage is quite lengthy and is unable to dive though it holding his breath.
1980's Local Chatfield, Minnesota caver Roger Kehret and others remove the rock talus lying in front of the cave mouth. Roger theorized that this multi year project would serve to lower the water level deeper into the cave, allowing an air gap to form at the sump. He also shared the vision that a large cave system lies beyond the sump.
1985
(Oct)
MSS members Larry Laine and Steve Porter use SCUBA to swim through the sump. They report that the cave passage suddenly becomes large again and they explore the main passage for over one mile before turning back. Larry and Steve determine it will be necessary to modify their diving gear before returning. The following year after modifications were made they make a return trip, but due to high water conditions they were not able to explore past their previous turn around point.
1987
(May)
Steve and Larry make their third trip into the cave and explore another mile past their previous turn around point. Due to time restraints and fatigue they turn around in the large main passage and retrace their journey out. They reported that the size of the main passage remained incredibly large and showed no signs of diminishing.
1987
(Sept 6th)
Roger Kehret formulated that it may be possible to lower the water level by several inches if a small amount of rock is removed from a constriction just before the sump that Larry and Steve previously dove through. He summoned Dave Gerboth and John Ackerman to assist. After several hours and bloody knuckles the water indeed subsided by several inches. A small V shaped air slot was now visible along the wall of the sump. John Ackerman was able to tilt his head into the slot and was the first non-diver to penetrate the sump. Roger and Dave followed, but in the process Roger broke his glasses and bloodied his nose. Roger and Dave retreated but John went on alone to explore the main cave passage for approx. three miles before turning around. He had a close call on the way out when he became lost in another wide near-sump. With his head tipped all the way back and his lips to the ceiling, he meandered around the sump, vainly searching for the way out. He stamina was stretched to the limit, and he could barely keep his lips to the ceiling. Thankfully he eventually chanced on the correct pathway and emerged back out into the main passage.
1987
(Sept 27th)
John Ackerman, Jason Engelhardt, Bob Vanderweit (An employee of John’s) and Dave Gerboth all make it safely through the sumps and resumed exploration. Early that evening John rounds a gentle bend in the main passage and discovers the “end” of the cave. Another sump is located here. On the way out of the cave John explores a side passage. Eventually the size of the passage diminishes, which forces John to slide forward on his belly. After ¼ mile John discovers a huge dome, perhaps the tallest in the State.
1987-2006 Because the main cave could only be accessed during low water conditions, combined with a dry forecast, very few cavers could or were interested in risking their lives to explore the cave system. Therefore only a small number of trips were made into the cave by various cavers over the years.
2006
(Summer)
John Ackerman purchases one acre of land above the cave, along with an additional 143 acres of subterranean rights, which includes the natural stream resurgence and three outlying caves.
2006
(Fall/Winter
John Ackerman makes numerous trips deep into the cave and compile data to create a safe man-made entrance into the cave from John’s property above the cave. Ted Ford, Charles Graling and Dave Gerboth assist topside.
2006
(Dec)
The newly created 124' deep entry shaft is completed.
2007

Exploration of the cave system, including scientific studies begin.

Harper Tyson’s grave is located in a local Pioneer Cemetery and work begins in an attempt to trace the family tree. Copies of the original land deed are obtained from the National Archives.

A gate was installed at the natural entrance and an informational sign was posted.

2008
(Apr)

John Ackerman, Dave Gerboth and Clay Kraus unearthed a prehistoric ice-age moose antler while excavating moist clay from a side passage they were exploring. Paleontologists were astounded at this discovery, because remains of this extinct species had never been discovered in this region of the United States.

Read the ACCOUNT

2008
(Jun)

While the Assistant Curator of the Illinois Museum (Chris Widga) was investigating the antler site in the cave, another incredible discovery took place. A scull belonging to a large sabre-tooth cat was discovered and was subsquently dated to be 27,000 years before present. Since the nearest sabre-tooth cat discovery site had been in Northern Arkansas, paleontologists across the United States were completely shocked at this event.

2009

Over 175 bones have now been discovered in Tyson Spring Cave and nearby Bat River Cave, resulting in the most significant scientific finding in any Upper Midwest cave. Other than the moose antler, all of the bones were found along the banks of the streams that flow through the caves. Most are extinct and rare specimens. Tyson Spring Cave is now one of the most important Pleistocene sites in the Northern United States. It will take years before all the bones are completely analyzed.

News of the discovery was eventually released to the media, and made headlines in newspaper and magazine forums.

Read the ARTICLE

2009
(May)

Penn State lab successfully amplified and sequenced DNA from the sabre-tooth cat skull. This is a profound event, and may be the first time that DNA has been extracted from a North American sabre-tooth cat.

2009
(Sept)

Geneticists meticulously deciphered the amplified and sequenced DNA from the sabre-tooth cat skull. They were astonished to find a 100% match to Homotherium serum, a saber-toothed cat that was even more rare than the Smilodon fatalis in the North American record. This is the first such specimen from the Great Lakes/Midwest region.

2012
(Oct)

Read the internationally publicized report on the amazing bone discoveries.

Download the REPORT

2014
(Jan)

John Ackerman, Emily Hudson and Brett Lucas explore a side passage, and discover a tall decorated dome with a stream passage leading off into the blackness. They follow the low (mostly water filled passage) on their stomachs and hands & knees for 1/2 mile before turning around. A return trip is planned for the following winter, when water conditions are low.

2014
(Nov)

Matt Covington's survey team is pushing forward, mapping the cave. There are many unexplored side passages to be entered and surveyed.

See the photo HISTORY

Bat river Cave
Pre settlement

Bat River Cave has no doubt been known since mankind first set foot in the area. A rippling cold clear stream exits the cave from the base of a limestone cliff and a natural limestone arch has no doubt been announcing the caves presence for thousands of years.

1971

Divers and cave explorers Larry Laine and Steve Porter investigate the cave, conduct a survey, and also produce a map.

1989
(Mar)

Larry Laine, Rich Ness and Vince Schuster entered the cave with diving gear in an attempt to dive through the water filled sump at the end of the cave. While they were making their way towards the sump the weather warmed up, melting the snow outside. They were somewhat concerned when they noted water flowing into the cave from three separate passages. They dropped their gear, went to the end of the cave and inspected the sump. They reported that it “had just enough room for a body” but went on to other projects and never returned.

2006
(July)

Tim Stenerson visits the cave and suggests that the sump be probed. Cave diver John Preston, John Ackerman and Tim Stenerson haul diving gear to the sump. Preston manages to penetrate the sump and surfaces on the other side. He reports a huge room with a stupendous waterfall crashing down along one wall. He discovers a large upper level above the falls and follows it for a distance before retreating.

2006
(Oct)

John Ackerman, John Preston and Phil Gemenden all dove through the sump hauling safety and survey gear. Ackerman hiked along the passages, holding the lead end of the tape while Phil read the compass readings. Preston followed up the rear, recording and adding information necessary to produce a map. Over one mile of cave was explored and surveyed. Thousands of bats were discovered hibernating along the walls. This was documented as one of the most incredible cave trips in the Upper Midwest.

2007
(May)

John Ackerman and cave diver Tami Thomsen dove through the sump, hauling 2 large dry boxes and one heavy equipment duffle. They made their way deep into the cave and chose two possible sites for a future man made entrance. They assembled specialized cave radio gear and transmitted signals to the surface, where they were received by Clay Kraus and Charles Graling.

2007
(April)

John Ackerman purchased one surface acre and 231 acres of subterranean rights to Bat River Cave from the surface owner.

2007
(Aug)

A safe 65’ deep man-made entrance shaft was created to the cave.

2007
(Fall/Winter)

Mapping and exploration of the newly discovered section resumed, and new cave segments were discovered and surveyed. Cave passages located upstream from the new entrance have not been explored yet.

2008
(Jan)

A bat count has been conducted and the results have authenticated the fact that Bat River Cave contains the highest concentration of roosting bats (over 4,100) in any natural cave in the Tri-State area.

2008-
2009

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 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 30 feet, and another large cave segment was discovered. The cave length is now approx. 2.5 miles as exploration continues.

Also in 2008-2009 rare bones dating back to the ice age were discovered along some of the stream banks throughout the cave. The artifacts are now being analyzed by the Illinois State Museum and are being compared to the incredible finds in nearby Tyson Spring Cave. Over 175 bones have now been discovered in Bat River Cave and nearby Tyson Spring Cave, resulting in the most significant scientific finding in any Upper Midwestern cave. Read the account

2009
(Feb)

News of the discovery was eventually released to the media, and made headlines in newspaper and magazine forums.
Major radio and T.V. stations also reported the fantastic findings.

2010
(Feb)

After traveling upstream over 1/2 mile on their stomachs through very low air spaces, Chris Nienow and John Ackerman explored and surveyed the continuing cave. Eventually, due to endurance limitations they turned around and made their way back to the entrance. This trip ranked as one of the most challenging and remote exploration trips to ever take place in a Minnesota cave. It is not known if cavers will ever reach the extreme fringes of this cave. The
surveyed length of this incredible cave is currently 2.84 miles. View the MAP

See the photo HISTORY

Holy Grail Cave
Late 1880’s

Speculating entrepreneurs attempt to gain access to an immense cave they felt existed behind the largest spring resurgence in Minnesota. The Odessa Spring project was so involved that a shanty town named “Odessa” sprouted up in front of the spring. Odessa Spring is located at the base of a towering bluff along the Upper Iowa River, which is the border between Minnesota and Iowa. The speculators followed the spring into the bluff by blasting a large tunnel, but eventually gave up after running out of funds. The town quickly died with the project.

1960’s-1980’s

Water from 12 square miles drains into the largest blind valley in Minnesota, referred to as the York Blind Valley. Cavers and geologists have always theorized that the water travels underground all the way to the Minnesota/Iowa border and emerges out of Odessa Spring. Dye traces performed by Ron Spong and Dr. Calvin Alexander have proved the theory. A vast underground cave system indeed exists.

1980’s-Present

John Ackerman, Dave Gerboth and fellow cavers searched for the York/Odessa Cave System by opening up caves in sinkholes along the suspected underground drainage corridor, including along the Upper Iowa River. Methods used involved hand digging and machine excavating. Diving was utilized in nearby springs. Miscellaneous caves were discovered, but none led into the Holy Grail of all caves, the York/Odessa Cave System. Download the STORY

2008
(June)

A catastrophic supercell rain event, which spawned brief hail, tornadoes and damaging winds hit Fillmore County. Eleven inches of rain pounded down in a short period of time. Major roads were flooded out and closed, and the town of Granger, located just north of Odessa Spring (along the Upper Iowa River) was surrounded by water. The Upper Iowa River crested at record level.

Dan Dornink, a fellow caver, lifelong resident of the area and Fillmore County Sheriff’s Deputy contacted John Ackerman. He described a gaping hole that had opened up during the storm event in a farm field, along the York/Odessa corridor. Dan and John contacted the 4 owners of the property (Ed, Glenn, John & Kay Ivers) and asked permission to investigate.

2008
(July)

With permission granted, Clay Kraus, Dave Gerboth, Dan and John descended 50’ down into the black abyss. While Clay, Dave and Dan were engrossed with a lead near the entrance shaft, John explored in the opposite direction. John detected wind blowing out of a tiny crack along the side of a narrow low passage and removed loose soil, sand and rocks. He followed the tiny void upwards, and then saw open blackness above him. He worked his way up into the void and stood up in a large room. He walked around the room but could not find the continuation, so again he searched for the source of the wind. Again he located a tiny crack with wind streaming out, and pulled away the loose sand and rocks. John entered a large passage and followed it for several hundred feet before encountering a stunningly huge intersection. Open blackness could be seen in both directions. He retraced the route back, regrouped with Clay, Dan and Dave, and together they explored beyond John’s turn around point. An amazingly huge cave system began to unfold before their very eyes. All wondered if this was part of the York/Odessa Cave System.

2008
(Aug)

John met with the 4 property owners and received permission to monitor the open sinkhole and to continue exploring the cave. John and Clay began to measure & survey the cave, and discovered the largest rooms, passages and pits known in any Minnesota cave. During one such trip they became lost, but thankfully found their way back to the entrance before dawn. Several weeks later John free climbed down a deep pit and stood on several large chock stones, which were lodged between the narrow walls. John could see a spacious deep body of water far below him. Without warning, the chock stones gave way, and as they crashed down into the open blackness John flung his elbows out against both limestone walls to hold his body up. In the process, he slammed his head against one wall, severing the electric connection on his helmet light. Hanging in total darkness, he was able to switch on his backup helmet light and managed to inch his way back up to safety.

2008
(Sept)

It was apparent that the cave system needed to be protected and the open sinkhole secured and capped. John met with the 4 property owners and offered to spearhead the complex project. He also began negotiations with the 4 property owners (and also the adjoining landowner) to purchase property with the intent of installing a safe dry entrance to this cave system. Exploration and survey trips continued, and major sections of cave were discovered, however the link into the fabled York/Odessa Cave System had not been located.

2008
(Oct)

John and Clay installed structural steel tube beams over the open entrance hole after reshaping the opening. High strength concrete was poured over the beams and a temporary culvert entrance was installed. The adjoining neighbor agreed to sell John acreage to install an entrance into the cave, but since the Iver’s were supportive of John’s quest to preserve, study and protect this unique underground wilderness, they agreed in unison to sell John 11 surface acres (located 300’ north of the temporary entrance) and 148 acres of subsurface cave rights.

2008
(Nov)

John completed the purchase, and exploration and survey journeys continued deeper into the cave system. The cave length reached 3 miles, nearly all of it lying directly under the property that is now legally protected by the Minnesota Cave Preserve.

A site was chosen for the new cave entrance, and a specialized rig drilled a small diameter hole to verify the accuracy. After the new entrance is completed the temporary entrance will be removed.

2009
(Feb)

The new 30” diameter, 65’ deep entrance to the cave was created and the original sinkhole that formed last year over the cave was completely backfilled. See video: http://www.youtube.com

2009
(June)

Fluorescein dye was poured amongst droplets that continually fall to the cave floor. Within several weeks the dye was picked up and identified by special receptors at the Odessa Spring resurgence. Positive proof has now been established that this cave lies directly over the York/Odessa drainage system.

2010

John Ackerman descends through huge precarious loose boulders and climbs down a cable ladder in a pit located deep in the cave, at the base of a huge passage called "The Gorge."
He discovers a swift moving stream - the first moving body of water to be discovered in the cave. Unfortunately after a short distance the stream changed direction and flowed into a wall with no air space.

2011

Numerous passages are discovered and surveyed. This amazing cave system is now over 4 miles long!
Cavers continue to explore this cave system in their quest to locate the passage that may lead into the elusive York/Odessa Cave System .

See the photo HISTORY


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