explore miles underground
of feet underground a bizarre world exists, a world where
streams disappear into cracks in the ground, translucent fins
of rock drape twisting passageways, and luminescent spires
of rock have slowly grown for thousands of years. There are
scores of miles of underground passages in the fractured bedrock
of the Driftless Region of Minnesota, Iowa, and Wisconsin.
Mystery Cave, Minnesota's longest, stretches for 13 miles.
Explorers have navigated 17 miles of passages in Cold Water
Cave, which begins northeast of Decorah, Iowa, and reaches
across the Minnesota border. Numerous caves lie beneath the
hills and fields of Fillmore County alone.
Few people see these places. Fewer still risk
their lives to discover new passageways, jamming their bodies
through tiny openings, dangling over rocky abysses, and diving
in freezing cold water beneath the earth's surface. But for
some, caving is a life-long pursuit, perhaps an obsession.
For years, St. Paul caver Steve Porter has
plunged over and over into murky depths in one of the most
dangerous forms of caving: cave diving. Some cave passages
are dry, while some have varying amounts of water dripping,
flowing, or surging through them. Others are completely submerged.
Sometimes these submerged sections lead to miles of caverns
that are only accessible by journeying through the watery
fissures. Cave divers use scuba gear to do just that.
"Cave diving is a ticket to a quick death
if you're not trained," Porter warned. It requires a
lot of gear, too. "Basically you have to have double
everything. If you have an equipment failure you can't just
go up to the surface."
Minnesota, the silt deposited in most flooded passageways
creates another issue. Lights can illuminate dark caves, even
underwater, but as cave divers disturb the silt around them,
they muddy the water and it can become utterly opaque. To
find their way back through twisting underground labyrinths,
cave divers must drag a safety line behind them. The line
is essentially a Hansel and Gretel-style bread crumb trail—it
enables them to find their way back out even when they cannot
see their hands in front of their faces.
However, the safety line can easily snag or
tangle, creating a life-threating situation, Porter discovered
on a fateful dive.
Porter was exploring a flooded passageway
with his partner when Porter accidentally let the line go
slack and becamed entangled in it. Unable to free himself,
Porter waited for his partner to help (per cave diving protocol).
Though, they had no means of communication, Porter's partner
realized what was going on. He struggled to free the line—it
was wrapped around Porter and his scuba gear. To make matters
worse, Porter had air trapped in his dry suit, causing him
to float inside the narrow passageway. The air bubble wound
up in Porter's seat and soon he was floating upside down,
with less and less air left in his scuba tank, wrapped up
in the line that was his and his partner's only ticket out.
"I'm starting to get concerned because
I can see all the silt come up," Porter described. "I
think, 'My gosh, if he can't get me loose when he can see
the line, how is he ever going to do it when he can't?'"
Unable to talk, Porter could only guess what
his partner was thinking as he continued fumbling in vain.
"I figured he'd start thinking, 'Better to have one fatality
than two,' and leave me there," Porter went on.
Porter thought about ditching all of his scuba
gear to escape the snare and sharing his partner's oxygen
on the way out. Porter felt his partner's hand on his stomach
and thought that he, too, had settled on this last ditch effort.
Then Porter felt him unzipping the dry suit.
"He was trying to open up my suit and
get the air out," Porter explained. "Because I was
upside down, he was having a hard time dealing with where
the entanglement was." With the air bubble out and Porter
right side up, perhaps he could be freed. Cold water rushed
into Porter's suit and he was righted, but his partner could
still not sort out the line.
"All of a sudden he was gone," Porter
said. His partner disappeared into the blackness in the direction
of the exit and Porter had no idea what had happened. After
waiting what seemed like an eternity, Porter realized his
partner must have gone to the surface. Porter had to do something
to save himself. He pulled on the safety line, praying the
thin cord would not break, and tugged, crawled, and heaved
his way through the flooded cave.
Utterly soaked and wrapped up in loops of
safety line, Porter fumbled his way to precious air. He and
his partner made it out safely that day, but it was just one
of many times Porter thought he might die. When asked if the
risk ever makes him think twice about going back, Porter said
he has thought about staying high and dry, but new caves and
new passageways are always beckoning him back down.
John Ackerman has gone to tremendous lengths
to discover new caverns, as well. The man has rummaged through
and shimmied under the wreckage of collapsed sinkholes in
hopes of finding openings beneath the precarious rubble. He
has used high explosives to blast through sections too narrow
to pass through. He has bored entrances through bedrock, and
he uses a modified track-hoe (a long-armed backhoe on tank-like
tracks) that he calls the "Cave Finder" to excavate
sinkholes and create entrances to caverns.
also spent a fortune buying land above numerous southeastern
Minnesota caves. Ackerman owns the access to most of the area's
caves and claims to have discovered over 40 caves.
"I think what attracts me to it is to
be the first person to walk through the inky blackness of
the unknown. You're the first human being to shine your light
through those passages since the beginning of time,"
Ackerman said. His enthusiasm for caves, he says, "is
like a hobby that just got out of control."
Ackerman pointed out the serious danger involved in his choice
of activity. "I don't want to say that I'm an adrenaline
junkie, but when you do something as dangerous as trying to
discover a cave there's a great deal of risk involved. Perhaps
the weather can change and you can drown, or if you're in
an unstable part of the cave you can hear what sounds like
sizzling bacon—that's a rock slide," he described.
"In Minnesota we have one added danger: the temperature
of the cave is 47-48 degrees. If you're lucky enough only
to get stuck in a cave, hypothermia can take you very quickly,"
acknowledged that what he does is more risky than run-of-the-mill
"When you're dealing with explosives
in caves, if you screw up once, you automatically die. It
forces one to be very careful," he explained.
cavers put their lives on the line. "I love thrilling
experiences, but I do not have a death wish," said Mystery
Cave State Park Manager Warren Netherton. "I do not go
into something that I do not fully expect to come out of."
Rather than risk death, Netherton and Iowa caver Ed Klosner
have devoted years of their lives to mapping caves. Global
Positions Systems (GPS) do not work underground, so the mapping
of caves is done the same way it has been for decades: by
measuring the dimensions and compass bearing of every single
room and passageway. Klosner and Netherton have been working
on this painstaking process at Mystery Cave since 2006. Netherton
estimated they will be done in 20 years. He laughed, but he
was not joking.
caves provides an invaluable record for future cavers and
scientists. Despite the effort, it has its own pleasure, too.
"Surveying caves is exciting because you get to see the
spatial relationships of all those interconnecting tubes,"
Netherton said. "It's a 3-D puzzle to try to figure out
how it fits together," Klosner explained.
Some have criticized Ackerman's bravado in
creating new entrances to caves as detrimental to fragile
cave formations, ecosystems, and groundwater. Ackerman contends
conservation is his goal.
Ackerman has put hundreds of acres above and
below ground into a private, undeveloped space he calls the
Cave Preserve. He has been undisputedly generous in allowing
scientists and experienced cavers to study and explore his
network of caves. Climate research, cave mapping, and paleontology
take place in his caverns. The skull of a saber tooth tiger
was found in one of Ackerman's Fillmore County caves, the
northernmost site of such a discovery ever documented.
When asked whether expanding access to so-called
underground wildernesses is counterproductive to protecting
them, Ackerman replied, "That just screams ignorance
in huge letters because you can't protect what you don't know
Winona State Univeristy geology professor
Toby Dogwiler agreed that allowing people to experience nature
is a key part of conservation. "The best way to protect
Yellowstone National Park would be to put a fence around and
keep everyone out, but if people can't see how beautiful and
special it is, then they won't care about it," he said.
"You can better conserve caves by making sure that people
have access to them," he added.
That said, minimizing one's impact while traveling
through a cave is important, Dogwiler said. The oil from human
hands can inhibit the growth of stalactites that are hundreds
of thousands of years old, so climb and crawl with caution,
Netherton advised cave-goers.
The greatest threat to Minnesota caves, Akcerman
contends, is not humans below ground but human land use above
ground. Agricultural chemicals, manure, and other pollutants
make their way quickly to cave waters, he said. Ackerman hopes
his Cave Preserve will prevent that at Minnesota's finest
has turned me into an avid conservationist because I realized
how fragile southeastern Minnesota is," Ackerman explained.
"If a tanker tips over, it's going to run into the nearest
cave and everybody downstream is going to be drinking that
water for eternity."
Klosner described seeing evidence of high-levels
of pollution while in Cold Water Cave. "It's eye-opening
to be in a cave and see foam in the water from agricultural
products," he said.
Hydrology ceases to be an abstract concept
after being inside the water cycle and seeing groundwater
firsthand, Netherton said. "Caves allow you to see where
our water goes," he explained. "What a unique place
for people to be able to go: between where rain falls on the
surface and the aquifers where it goes."
"Because of years of marketing, people
have an idea that spring water is pure," Dogwiler said.
"There's very little opportunity for natural processing
and attenuation of contaminants [in Karst groundwater]. Whereas
in a non-Karst aquifer there's time for chemicals to break
down or absorb into clays."
caves are born
In Minnesota, significant caves only exist
in the limestone and dolomite of the Driftless Region. They
form when rain water, which is naturally slightly acidic,
flows through cracks in the limestone and dolomite bedrock,
dissolving the basic (as in high-pH) rocks and creating conduits
through the bedrock. "If they are large enough we call
them caves," explained Dr. Toby Dogwiler of Winona State
In those caves, some of the dissolved rock
is left behind by dripping water. Over thousands of years,
this forms all manner of oddities, famously the spike-like
stalactites and stalagmites. All of the deposits are essentially
variations on this theme, but an incredible assortment exist.
Passages are alternatively decorated with needle-thin "soda
straws," ribbons of "bacon," and oozing blobs
of once-dissolved minerals.
This interaction between bedrock and rainwater
makes the region's foundations as porous as Swiss cheese.
This Karst topography, as geologists call it, leads to caves,
sinkholes, and streams that vanish into the underground.
Do not call it spelunking. The term is passé
among cavers. They go caving. Sport cavers, cave photographers,
cave ecologists—people go beneath the surface for all
kinds of reasons, but they all urge would-be cavers to get
connected with a caving club or "grotto." Rogue
cavers tromping through these fragile and rare phenomena is
frowned upon, Dogwiler explains. What is more, caving is incredibly
dangerous for beginners, and underground accidents require
many people to undertake a risky rescue effort. By connecting
with a caving group, novices can learn from experienced cavers.
More information is available at www.mss-caving.org (Minnesota
Spelogical Survey) and www.minnesotacavingclub.com.
Mystery Cave State Park offers wild caving
tours during the summer. Mystery and Niagara caves also offer
more accessible trail tours.
For more information on the Cave Preserve