Southeast Minnesota caves steeped in lore
Jul. 25—ROCHESTER — If you happen upon a depression in a hillside, a hole in the ground that leads to water-carved tunnels, know this: Jesse James likely never slept there.
Furthermore, no horses, thieved or otherwise, were kept within those stone walls on a clandestine basis.
And if you're hoping to find evidence of Native American habitation reaching back to the last glacial epoch, well, don't go looking underground.
With its karst geology and sandstone hills providing a perfect place for caves, the underground realms of Southeast Minnesota have a surprisingly short history.
"Jesse James is a big one," said John Ackerman, founder of the Minnesota Cave Preserve and the Minnesota Caving Club. "A lot of things are rumored to be a Jesse James hideout, and it's just a depression in a hill."
Founded in 1989, the Minnesota Cave Preserve owns eight cave systems in Southeast Minnesota that feature 45 caves, 724.4 surface acres and 1,300.33 acres of additional subterranean cave rights. For the most part, these caves were discovered, Ackerman said, in the 20th century, so any fanciful tales about Indigenous people or Wild West outlaws are just that: fanciful tales meant to entertain more than inform.
"Back in the 1800s, if there was a cave that prominent, it'd be on postcards," Ackerman said. He pointed to Tyson Spring Cave, which had a known passage of about 800 feet. That cave was photographed and made into postcards. Furthermore, the stream that came from the cave was used as a source of fresh water. Had other caves been discovered, Ackerman said, it stands to reason they'd have been similarly celebrated.
"One thing that we do know for sure is the caves in Minnesota, with the exception of a few, have never been opened before," he said.
Sinkholes, which are often the entry point for caves that have been discovered in the 20th century, were known, but Native communities generally had cultural taboos against exploring deep underground. So, it took European settlers to start exploring the underground networks carved into the limestone of the subterranean karst landscape.
As for pre-settlement known caves — Tyson Spring Cave and Bear Den Cave are a few Ackerman named — he said, "You'll only find a couple of those in Minnesota."
Rochester is home to several underground structures, but most were not carved by water.
At
Stoppel Farm at the History Center of Olmsted County,
a cave is actually what Ackerman would call a storage tunnel that was carved into the sandstone by settlers. The same is true of the
cavern at Quarry Hill Nature Center.
Lori Forstie with Friends of Quarry Hill Nature Center, said the cave at the public park was excavated by patients at the Rochester State Hospital, which used to occupy the site. Thomas Coyne, a patient at the hospital, began work sometime before Sept. 1, 1882. By the end of 1884, the biennial report noted that the horseshoe section of the cave — including space for storage of apples and butter — was completed. The additional section, which is now the main entrance, was added later.
"The cave was not a natural feature, but rather carved into the naturally occurring sandstone layer of rock for the specific purpose of creating food storage," Forstie said. Other than its use for food storage in the era before refrigeration and now as a site for historical tours, the cave has not had any other purposes.
A bit of online spelunking reveals the biggest bit of cave lore in Rochester.
Located just south of Rochester Community and Technical College in the trees between the southwest student parking lot and U.S. Highway 14 is a cave known to some as
Horse Thief Cave.
No horses or thieves were present.
Ackerman said the "cave" is actually a man-made tunnel. Furthermore, it was created by a farmer who once owned the land.
City of Rochester Parks and Forestry's Mike Nigbur said the city doesn't have any maps of caves, though there are rumors of a small cave — an online eye-witness on Reddit mentioned seeing bottles inside — in the Indian Heights area probably on the Assisi Heights property. A house Viking Hills area is reputed to have a small cave on its property.
Ackerman said one of the problems with Rochester is the limestone is fractured, meaning the water was not forced to carve out caves through the millennia.
Fillmore County, he added, is another story. The county is home to an estimated 400 caves, and is known as the sinkhole capital of Minnesota. The county is home to two caves that draw thousands of visitors a year.
Aaron Bishop, whose
family has owned Niagara Cave near Harmony, Minnesota, since 1995,
said the cave was unknown before 1924. The cave was discovered when three pigs fell into a sink hole. The pigs were rescued, but the cave was not greatly explored until eight years later when a group of spelunkers visited and explored deep into the cave.
By 1934, the cave was open for tours, closing only during World War II and the COVID pandemic.
"We are all on top of the limestone," Bishop said. "It's the calcium carbonate that forms the bedrock, and the cave systems formed within limestone within tens of thousands of years."
In the
90-plus years that the cave has been fully explored,
not much has changed, Bishop said. During the spring melt or heavy rain events, rocks will tumble through the stream that runs through the cave. In the wedding chapel, some of the straw stalactite have grown, which adds to the beauty of the chamber.
"In the grand scheme of things, we haven't noticed any change," he said.
Rain events will bring soil sediment that needs to be cleared out.
Bishop said he's also heard the Jesse James stories. Are any of them true?
"Time is pushing some of those stories away," Bishop said. "It's hard to know what exactly is truth at that point."
At spring sites where underground rivers come back to the surface, Bishop said, people often built milk houses to take advantage of the constant 48-degree temperature.
Greg Anderson, assistant cave manager at
Forestville Mystery Cave State Park
near Preston, said that cave was discovered on Feb. 3, 1937, when Joe Petty, who gave tours at what is now called the old Mystery Cave, saw a sinkhole in the snowmelt and dug around near a tree root and some rocks to uncover the entrance to the current Mystery Cave.
While no horses were hidden at Mystery Cave — Anderson said the cave system was known to man before the day it was discovered by Petty — the cave had a mule.
"A lot of rock had to be removed from the rock garden," Anderson said, referring to a section of the cave. "Joe had a small mule named Jenney who he used to pull a three-wheel cart up and down the passage."
A flood on June 28, 1942, washed away two buildings near the entrance of the cave, including the 30-by-30-foot visitors building, which was found about a mile away. For years, he said, souvenirs, tickets and cash from the building were found in nearby corn fields.
That flood closed the cave for about four years. When it reopened, for a time it was a designated Cold War fallout shelter for the region.
"They had barrels of food and water, nonperishables, stored in the cave," Anderson said. "We have the fallout shelter signs on display here."
In 1988, the state of Minnesota bought the land as part of the state park. Concrete walkways, railings, bridges and conduits for electricity were installed — the latter being hidden within the rock as best as possible.
"We try to keep the lighting as natural as possible," Anderson said.
The cave, with 13 miles of mapped passages, sees about 25,000 visitors a year. The South Branch of the Root River goes underground and helped create the cave.
"When it's dry out, water goes completely subsurface," Anderson said. "It comes out at Seven Springs about a mile and a half away. it comes out at 48 degrees and becomes a wonderful trout stream."
