Spring Valley Caverns


Tyson Spring Cave December 2006


The gaping mouth of this cave system lies directly below a cluster of towering limestone bluffs in Fillmore County. And out of its inky black mouth flows a tempestuous vibrant volume of water, which cascades down large stair stepping blocks of rock, beginning its journey through the descending forested valley.

When I first laid eyes on this resurgence I was smitten, as I know previous generations must have been, dating back to the arrival of the Native Indians. Because the setting is almost utopian, no doubt our ancestors chose to make arduous journeys through the wild terrain in order to spend quality time there. But due to its remote site, historical information is in short supply. We do know however, that shortly after the War of 1812 the United States government gifted approximately 120 acres to a war widow, who then deeded the property to Mr. Harper Tyson in 1862. He was obviously very proud of his cave, and sometime between 1875-1885 a professional photographer, who utilized the stunning new stereoscopic method, photographed the idyllic cave resurgence. Another historical photograph, taken by a succeeding landowner, can be found in the Fillmore County Historical archives.

It has been reported that the resurgence was a favorite picnic setting back then and that folks could venture into the 800-foot long cave using wooden boats. Unfortunately these early adventurers were prevented from penetrating deeper into the cave because the main passage ultimately became totally submerged in water. How frustrating this must have been, because during low water conditions it is almost certain that they could clearly hear a vivacious turbulent waterfall through tiny air gaps along the ceiling.

It wasn’t until the advent of wetsuits that explorers could finally wade through the bone chilling water to inspect every foot of this cave in hopes of finding a route around the water filled passage. During the 1960’s and 70’s Ron Spong, founder of the Minnesota Spelological Survey, made multiple attempts to breath dive and snorkel through the water filled passage but was unsuccessful. During the 1980’s a well known local caver, Roger Kehret, focused on the idea that if the talus pile of rocks just outside the entrance could be removed it may lower the water level inside the cave by several inches. He theorized that several inches of water was all that stood between himself and the continuation of the cave.

In 1985, while Roger was still actively pursuing his goal, MSS members Larry Laine and Steve Porter successfully dove through the sump using SCUBA gear. They returned with the good news that the cave indeed continued deeper into the unknown. Due to dangerous water conditions and the need to modify their diving gear, the second penetration into the new section did not occur until the following year. A third trip was made in May 1987.

In the meantime Roger was like a locomotive train, making deliberate and steady forward progress in his attempt to lower the water level so that non-divers could explore the cave. His efforts paid off and by now the water level had been lowered enough so that the tiny air gaps along the ceiling allowed safe passage deeper into the cave. Just after passing through this dangerous area the fabled waterfall was encountered, but soon thereafter the passage became totally water filled. On September 6, 1987 Roger summoned Dave Gerboth and myself to the cave for what he felt was the final hurdle in lowering the water level. Roger was confident that if a few inches of rock were broken away from a constriction near the waterfall that the result may be a slightly lower water level.

The three of us transported a sledgehammer and large chisel to the site, and after three hours we managed to chip a few inches off the top edge of the constriction. By now my knuckles were beaten and bloody, and because the water was so cold my hands were almost numb. When we turned around to inspect the water filled passage we were elated to see that a small “v” shaped air gap had opened along the edge of one wall. We were all speechless as we felt and heard a torrent of air screaming through the newly created space, beckoning from beyond. I managed to tilt my nose into this tiny cavity and worked my way slowly ahead, into blackness. Eventually the air space grew and I found myself standing in a large spacious passage-the third person to do so, and the first person to enter this new cave system without SCUBA gear.

Soon Dave and Roger successfully worked their way through the slot without extinguishing their carbide lamps and together we began to move deeper into the cave. Unfortunately Roger had bloodied his nose and had broken his glasses during his foray through the slot passage and as a result decided to retreat with Dave. Without any consideration for safety I went on alone. I seemed to be drawn deeper into the cave like a magnet. This place was alive and vibrant. The turquoise blue water ebbed and flowed over numerous calcite dams and collected here and there into deep cavities, some of which required me to swim across. The further into the cave I traveled the more astounded I became. The main passage became wider and taller, and as I crested a bus sized limestone block I found myself standing in a huge room with a sandy floor. After catching my breath momentarily I rejoined the main stream passage, where the formations grew in size and color. After traveling one mile through this labyrinth I was totally awestruck.

Eventually I came upon another sump but could see several inches of air space and so I decided to risk it once again. This almost proved to be a fatal error on my part because I actually became lost in this passage with my lips scraping against the ceiling. I meandered throughout the icy cold pitch-black passage, sniffing for a way out, any way out. My neck muscles were eventually so fatigued that they were almost unable to hold my lips to the ceiling. Finally I made the correct turn and popped out into the continuation of the huge cave passage. Hours later, after traveling almost two more miles through stupendous cave passages I turned around and made my long solo journey out. Along the way I was enthralled by the dynamics of the stream passage and understood my fate if it were to rain outside, causing the water to rise even one inch. Why I thought I could cheat death I will never know. Maybe it was because I understood that great discoveries involve great risk.

Three weeks later fellow MSS caver Jason Engelhardt, my employee Bob Vanderweit and Dave accompanied me into the cave to continue the exploration. The day wore on and the miles passed us as we traveled past the original place where the divers had turned around. Our legs were beginning to feel a bit like rubber. My mind, however, was in overdrive. My anticipation peaked as I rounded each bend and marveled at the sights and sounds that lay before me. By early evening the others were trailing behind, and as I rounded another bend in the passage I discovered the route ahead was blocked again by water. I had found the “end” of the cave, but nonetheless, my adrenaline level was still soaring and I felt like I was flying.

On the way out of the cave while the rest of the party took a break on a sandy bank, I trekked solo down a long narrow side branch. The first part of the passage was very friendly but eventually the ceiling hunkered down and I had to move forward by crawling on my hands and knees. After a few hundred feet the ceiling became lower yet and I was forced to slide ahead on my belly. Eventually my belly and my back were both pressed tightly between the floor and the ceiling, and every little cobblestone that I slid over dug into my chest. I could hear a thundering echo ahead and so I was mostly oblivious to the pain. After following this passage for over one quarter mile the ceiling finally rose up, and as I stood up I was dumbfounded at what my eyes were seeing. I had discovered an incredibly tall decorated dome, perhaps the tallest in Minnesota. As I reveled at this stupendous dome, with my neck cocked all the way back, I felt a sharp pain in my right rib cage. Intuitively, I reached down inside of my wetsuit and pulled out an off-white golf ball sized cobblestone! This little nugget must have made its way there as I was bulldozing along the passage. For some reason I thought of it as a well-earned prize, and so I stuffed it safely back inside my wetsuit and began the journey back. When I returned to my van that evening I placed my special prize in a nice little niche inside the dashboard console.

I had been the first human to reach the far depths of this cave system and the experience had been etched into my very being.

Part two

I was 33 years old when I made that epic trip into Tyson’s Spring Cave and it has remained seared into my consciousness ever since. To this day I still have that special beige cobblestone, which I have kept in each one of the nine vans I have owned since then. One recent sunny afternoon as I was parked on a St. Paul side street waiting for a customer to arrive, I casually removed that memorable cobblestone from the little niche below my dashboard. And as I rolled it around in the palm of my hand memories of the cave came back to me with startling lucidity. Then it dawned on me that it had actually been 19 whole years since I had been in Tyson Spring Cave. As unbelievable as it must seem to most people, including myself, I had tested my luck countless times throughout the years and actually lived to see my 52nd birthday. As I deliberately placed the cobblestone back in its special compartment I paused for as few moments and then made an unyielding pledge right there and then that revisiting Tyson’s would be a top priority.

And so it would be.

Two weeks later I found myself standing at the mouth of the cave, and that very same morning I disappeared into it, on my way to retrace my original journey into this amazing cave system. Although I had a support team available, I chose once again to make a solo reconnaissance into this formidable tempestuous cave system.

As I navigated through the low air spaces, the labyrinth of swims, negotiated over and under immense dislodged blocks of limestone, and strolled amongst massive delicate formations, the awesome presence of this 3.5-5-mile long cave revealed itself once again. Upon reaching the immense dry room, I paused momentarily, gazed from end to end, and continued my journey deeper into the cave. I felt strong, electrically charged, and honored to be a witness to such an incredible environment. As I resumed my excursion along the main gallery, the formations appeared to be even more abundant, pristine, and grandiose than I had remembered 19 years ago. As I rounded a gentle bend in the passage, I abruptly paused under a large shimmering transparent formation, and glancing down at the myriad of colorful cobblestones on the floor, one in particular caught the glimmer of my light. It was beige, and was about the size of a golf ball. As I embraced it in the palm of my hand, my eyes returned to the immaculate formation overhead, and right then and there I made a firm commitment to myself that this cave system would forever remain pristine.

Today I am so pleased to announce that Tyson Spring Cave will indeed be perpetually protected. The Minnesota Cave Preserve has purchased property over the cave system and has secured subsurface rights, which includes the natural stream entrance and four other outlying caves. A 115-foot deep access shaft has now been created into the magnificent Tyson Spring Cave system, which will allow safe entry to cavers and researchers. I would like to thank Dave Gerboth, Charles Graling, Ted Ford and many others who have helped make this historically significant project possible. My heartfelt appreciation goes out to Clay Kraus, who was instrumental in making this vision a reality.

John Ackerman



Read the HISTORY


Tyson Spring Cave History