In February 1966 John Latcham purchased a 470 acre farm (A Contract for Deed) located just north of Spring Valley. Several months later, this 27-year old farmer discovered what he surmised was a newly opened sinkhole while searching on horseback for a lost calf. He slid through the narrow opening, and until his eyes adjusted to the inky blackness, he squinted into an expansive seemingly endless cavern. He was astounded at the immense passage that stretched out of sight before him, and upon returning to the surface he immediately proclaimed that he had discovered a vast incredibly decorated underground treasure.

Before the day was over, experienced cavers (such as Jim Rolbiecki pictured here) were summoned to explore the cave. Based on the amount of lichen growing on the outcropping it has been surmised that Spring Valley Caverns could have been open to the surface and entered by previous generations.

John Latcham hired a road contractor to construct a road to the cave, had electricity brought to the site, hired electricians to illuminate the cave, and construction crews to make a high platform and stairways within the cave. John, Roger, and a team of laborers groomed the trails and spread pea gravel along the main cave passages. Shown above is the front cover of a brochure that touted Spring Valley Caverns as one of the most scenic caverns in the Northern Central United States. 

In 1968 this WWII Quonset building was placed over the entrance. Tour guides were hired and tourists began arriving. Unfortunately the unpaid subcontractors placed liens on the operation and the following year the fee owner of the farm foreclosed due to non payment. The farm was sold again to a new owner who kept the cave operation open through the 1971 tourist season. The Quonset building and the cave remained locked up for 18 years until purchased by John Ackerman in 1989. This photo was taken in 1997.  

The average depth of the passages below the surface is 65 feet, however, some passages plunge 120’ below the surface.

Most passages are dry; however a major stream flows through an extensive lower level.

Water carved out all of the passages and rooms in this cave system.

John Ackerman and Dave Gerboth followed this passage until it narrowed down to a few inches. After working almost one year to enlarge the crack, John broke through on April Fools Day 1990, and discovered almost 5 more miles of astounding cave passages.

An absolutely breathtaking example of pure white flowstone with tiny terraces and cave pearls.

A massive wall flow, thousands of years in the making.

This room is aptly named the Colossal Room. John Ackerman discovered upper level passages near the ceiling.

The lower stream level, where the Lost River flows. There are three waterfalls along this lower level.

Brisk 48-degree water constantly flows out of this hole alongside a main lower level passage.

John squeezed through this passage he had been widening and discovered another major section within Spring Valley Caverns.

This photo is titled “First Footprints” and was taken shortly after the breakthrough.

When a cave explorer discovers and explores a prehistoric cave passage for the first time, the feeling of awe and respect is overwhelming.

A delicate soda straw with a drip.

A total of 35 other caves have been discovered on the Cave Farm in addition to Spring Valley Caverns. The caves have been discovered by digging in sinkholes. This was a very dangerous job, and in more recent times backhoes were brought in to assist in the endeavor.

A 1991 group effort at the Cave Farm, focused on finding a new cave. Battery powered lights had just become available as seen on several helmets to the far left of the photo.

A cave was discovered during this excavation in 1994.

While sinkholes are excavated a caver may uncover rocks with white dots. Underground air movement forms condensation on the limestone and leaves behind white calcite mineral dots. Checking for air movement is also an important clue. It indicates that a large cave system is most certainly connected to the sinkhole.

Dave Gerboth & John Ackerman in 1987 after discovering Ackerman’s Cave.

1993 photo of John Ackerman discovering a very tight, muddy and cold stream.

Phil Gemuenden and Matt Potter are pros at finding new caves. Photo taken in 2002.

Dave Gerboth pushes forward in Corn Pit Cave. Photo taken in 2005.

2004 Photo of Clay Kraus and John Ackerman after opening King Cave.

After we expose a gap at the base of a sinkhole we attempt to enter the cave. Usually the openings are tight, and one never knows what to expect.

After 6 feet the ceiling in this cave rose up to thirty feet.

Sometimes a deep pit or crevice is immediately encountered. Using a rope for a hand line can be a life saver.

Entering a cave for the first time is the thrill of a lifetime. There may be miles of large unexplored caverns just ahead.

When entering a cave for the first time it is wise to bring a compass, tape measure and a survey book. Getting lost in a large cave system can cost you your life.

Sometimes we inch our way through low water spaces in hopes of discovering miles of cave passages. When the air space diminishes to several inches it is important to move forward very slowly so water does not splash down your nose and into your lungs.

Hand excavating sinkholes in an attempt to discover caves was risky business. In 2002 John purchased a trackhoe, and promptly modified the machine so it could reach greater depths.

Now we have the ability to excavate all of the soil and loose rock from the entire sinkhole in hopes of locating a gap that will lead into a cave system. Care must be taken so that the 30,000 pound Cave Finder does not slide down into the gaping hole while lifting heavy loads or doing something stupid.

Like this.
Here the Cave Finder reaches down for every inch.

The force of a falling rock from above can easily break a neck or back. This sinkhole has been excavated, and a small gap was uncovered in the base. A cave was later discovered.

A specially constructed man cage is pressed into service to protect the cave explorer from falling rocks or collapsing walls in deep sinkholes.

This is a bird’s eye view of an average sinkhole in S.E. Minnesota. Trees sprout up along the perimeters and farmers simply farm around them. This sinkhole is about 20’ deep.

Excavating sinkholes is not as easy as it may appear. Occasionally water may leach from the newly exposed sides and flow into the immediate digging area. In this case the Cave Finder became hopelessly mired in muck and had to be pulled out by huge machinery.

In this case the Cave Finder had just dug 40’ down into the base of a sinkhole, where a small cave was discovered. A sudden torrential rain event occurred and rapidly filled up the sinkhole. John extended the boom against a tree to prevent the machine from sinking out of sight. Again, heavy equipment rescued the Cave Finder.

The Minnesota Cave Preserve provides hands on opportunities for the young and old alike.

Quarry Hill Nature Center and the Rochester School District have unlimited access to the Cave Farm/Spring Valley Caverns. Their well seasoned guides lead groups through the caverns free of charge.

Nature organizations are thrilled to experience the wild pristine nature of the caves. The caves on the Cave Farm have not been commercialized or artificially illuminated.

State and County governmental agencies utilize the Cave Farm to learn first hand the relationship between sinkholes and the subterranean world.

There are almost 700 acres of hardwood forests, limestone bluffs, major creeks and natural prairies to explore on the Cave Farm. This unique setting provides many educational opportunities.

College outing groups and geology students make use of the Cave farm - even in the winter months. The temperature is always 48 degrees underground.

Scout leaders, who have been trained to lead cave trips, take scouts through the caves. Some groups camp out for the weekend. Someday these kids will be making decisions that affect our precious resources.

In 1991 it was decided to restore this huge trash filled sinkhole located on the Cave Farm. Since the 1800’s it served as a private dump for the landowners.

This was an daunting project, but work began by hiring a backhoe service to remove large items.

Wood debris was burned and trash was placed in assorted containers for recycling.

The large tank shown in the rear of the photo was found to block voids leading to subterranean passages.

Numerous media organizations followed the restoration process and one of the video documentaries was beamed via satellite to 55 million cable subscribers across the US, Canada and Mexico.

Dozens of decomposing batteries and leaching farm chemical barrels were uncovered. A large section of Spring Valley Caverns was found to run directly under this sinkhole. A trail of trash runs hundreds of feet through the cave before dropping into a series of pits and into the water table.

Ted Ford and his crew were kept busy transporting metal to a recycle center.

A commercial grade silt liner was installed at the base of the sink and several truck loads of large rock was placed over the liner.

Native grasses, shrubs and trees were planted. The local Soil and Water Conservation Dept. began taking their constituents to the above and below ground site for a graphic demonstration on the relationship between surface and subsurface.

Phil Gemuenden prepares to plant hardwood trees on the Cave Farm. Over 100 trees of various species have been planted on the Cave Farm to jump start restoration in overgrazed areas.

Finally after over 20 years of constant badgering and legal threats, a sagging portion of BP's oil and gas pipeline was finally "stabilized" in 2013 instead of replaced. This ancient pipeline still lies directly over an open hole, at the exact spot where a stream drops straight into Spring Valley Caverns and travels for miles until it once again reaches the surface. Shame on BP for prioritizing profits over human life and our fragile subterranean environment.

In 2016 the largest contract for the Conservation Reserve Program in Fillmore County was awarded to the Cave Farm. Almost one hundred fifty acres was planted with prairie seeds, and in 2019 a prescribed burn was conducted, which enhances the prairie growth.

In 2015 No Till farming was established on the Cave Farm, and an emphasis on planting cover crops such as alfalfa was instituted.

The Original WWII era Quonset building that was placed over the entrance to Spring Valley Caverns in 1968 is shown here before demolition.

A major excavation project opened up the original natural sinkhole entrance on the left. The opening on the right reveals a major passage that was discovered within the cave in 1995. Plans were drafted to place a building over the top of both entrances.

A prominent bridge contractor was chosen to construct the unique building. The completed building will be almost completely buried in the ground, and as such must be heavily fortified to withstand the pressure.

Work began on the main level of this three story 38’ tall building. Tons of rebar were utilized in the construction.

Reinforced 18” thick concrete walls were poured.

The interior walls of the building were constructed to simulate hand hewn limestone rock construction.

Pre-stressed concrete roof panels were installed. The roof will be underground upon completion of the project.

The roof has been installed, the windows and doorway completed, and the archway pad was poured.

Work began on the limestone entrance arch. The pipe on the left of the photo enters the cave in a lower level wall and serves as a bat access.

The entire site was backfilled. Native grasses and trees were planted. This building serves as a gathering place for nature groups, scientists and cavers before embarking on their underground journeys.

Artifact Sink before excavation.

Bottles and assorted debris was removed before the project began. Like most sinkholes, this one was used as a dump by the original landowner.

Beginning to remove fill.

These antique bottles were uncovered during the excavation process and were donated to a Fillmore County collector who specializes in bottle preservation.

Various pots and bottles were uncovered down to the 10 foot level.

Some were intact and valuable.

Beginning to uncover what was originally a spacious cave passage.

In order to facilitate the removal of sediment (carried in by the last glacier deposits and modern day field erosion) Phil Gemuenden’s tractor was lowered down into the sinkhole.

Work begins in earnest.

Could this lead to miles of undiscovered passages?

A graphic photo showing what lies under farm land in Fillmore County. This cave passage may have been here over ½ million years ago before getting plugged up with recent glacial till.

Sediment removal reached the 100 foot mark with no end in sight. A tiny camera was snaked ahead almost 30’ through a slender air space to reveal that the passage continued forward. Unfortunately it was almost totally plugged with sediment. This project was subsequently terminated and the sinkhole was restored.

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Identifyng climate change.

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John Ackerman describes the cave layout to the OMNIMAX team who filmed footage for the film "Ancient Caves." This outstanding film premiered at the Science Museum of Minnesota and is now being shown internationally. VIEW THE PREVIEW

The OMNIMAX team films "Cathedral Hall" in Spring Valley Caverns.

John Ackerman at the Science Museum of Minnesota display of the saber tooth cat and the moose antler discovered in Tyson Spring Cave.VIEW THE PREVIEW

Rudy Larsen, Martin Larsen and John Ackerman at the Science Museum of Minnesota display of an ancient stalagmite from Spring Valley Caverns. March 2020.