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Wisconsin Natural Resources magazine

Wisconsin Natural Resources magazine

Caving is a fun family activity that can feed interests in outdoor sports, exploration, science and adventure under foot. © Kasey Fiske
Caving is a fun family activity that can feed interests in outdoor sports, exploration, science and adventure under foot.

© Kasey Fiske

October 2007

The world down under

Caves in Wisconsin? You bet! We can help you find them and explore them.

Judy Nugent


Types of Wisconsin caves
Adventure seekers
Dos and don'ts
Public limestone caves
Why are people cavers?

To the Batcave, Robin!

No this isn't Gotham City, though we have one in Wisconsin, but who would guess that there are caves around the state large enough to fit the Batmobile and Wayne Manor? Well, it's true. And what you'll find inside can be even cooler than Hollywood's latest thriller – weird rock formations that look like they're from another planet, fuzzy bats clustered in far corners, an icy chill that brushes across your face, and strange carvings of buffalo who roamed the Midwest centuries ago. Sure makes going to the movies sound dull. Instead, pack up your family for an adventure they are sure to remember. Take them caving!

Types of Wisconsin caves

There are two types of caves in Wisconsin – limestone and sandstone. Limestone caves are the ones you might typically think of – stalactites dripping from the ceiling, dark, wet places with steady cool temperatures, and bats lurking in the corners. These caves are found in limestone rock formations and are the most prominent type found here. Sandstone caves formed primarily in the southwestern part of the state and are sometimes merely rock outcroppings or shelters. These tend to be much smaller and drier than their limestone cousins. Both types of caves offer opportunities for fun and adventure. The easiest to access are a few of the larger limestone caves that are open to the public.

Once inside a cave, curiosity soon takes over. How were the caves formed? Who found them? What are the different rock and mineral formations on the walls and ceiling? Why it is cold and damp?

As luck would have it, no two caves are alike, just as you never step into the same river twice. Each cave is ever-changing and water constantly shapes the landscape above ground and underground.

Kasey Fiske, vice chairman of the Wisconsin Speleological Society (WSS), knows a lot about caves. "Limestone caves are also known as 'solution' cave that formed by the dissolving limestone rock as the surface came in contact with water that is slightly acidic. It is sort of like seeing an Alka-Seltzer™ tablet dissolving in water."

Looking into vast caverns and rooms with high ceilings, it is hard to imagine Alka-Seltzer™ getting the job done. A key component is time – millions and millions of years of constant dissolving. Fiske explains, "As rain water soaks into the ground, it filters through leaf and other organic matter, drops off larger particles and picks up dissolved carbon compounds. These carbon compounds combine with water to form a mild solution of carbonic acid. If there are some remnant petroleum products in the limestone, sometimes the sulfur compounds in the petroleum products attach themselves to the water and dissolve forming a mild sulfuric acid. Both of these acids will dissolve the limestone rock.

Water seeping through limestone slowly forms hollow tubes called soda straws. © Allen and Chris Lewerer
Water seeping through limestone slowly forms hollow tubes called soda straws.

© Allen and Chris Lewerer

Water containing the mild acid solutions flows through the limestone rock formations following cracks in the earth's crust. As the mild acid dissolves the limestone the cracks get bigger and form passages. Some of the dissolved limestone and water comes in contact with air and re-solidifies. That is what makes formations inside the caves.

Most of Wisconsin's limestone caves were formed in this manner over millions of years, and the results inside can be spectacular. The different features that decorate a cave are referred to as cave formations or speleothems. The most common speleothems are familiar to people, even if they can't remember which is which. They are stalactites and stalagmites. Stalactites are the ones that "stick tight" to the ceiling, while stalagmites build up from the cave floor. These deposits of calcite are concentrated along cracks where the water drips through the rock and dries out. In fact these formations are often referred to as drip stones or flow stones. They form much as an icicle does in the winter, constantly dripping and leaving a little more calcite to crystallize.

Another type of speleothem is known as onyx, Fiske says, "Onyx is a highly crystallized form of rehardened limestone that covers the ceilings and formations in a cave and can sometimes be several inches thick. It begins as a liquid solution and attaches itself to rock as it dries out. It is a lot harder and more glass-like than normal limestone, so the formations often appear very different from usual, as if they have been coated with milky glass."

There are also "popcorn speleothems," small formations made from drippings or splashing liquid on the floors. Where lots of these little bubble growths are clustered next to each other, it does look like popcorn.

Some caves also have box-work formations. These are thin blades of calcite that hang from the ceilings or stick out from the walls. They go every which way making a honeycomb pattern. The blades can intersect at various angles forming boxes, hence the name. Wind Cave in South Dakota is one of the best examples of this, but box-work formations also are found in some Wisconsin caves.

Only about 250 sandstone caves have been recorded and mapped in the state. Sandstone caves are also usually cool in temperature, but they are dry and are generally much smaller than their limestone cousins. The longest one in the state is 100 meters in length, but most are tiny by comparison. Sandstone caves are usually barren and lack the more typical cave formations because they don't have mineral-rich water dripping from the ceiling. Some of these caves were formed through dissolution, but most were formed by running water and wind erosion centuries ago.

Sandstone caves were used by Native Americans as places to live and visit. We can tell from the excavations of sandstone caves and rock shelters, that Native Americans would spend their winters in and around these caves that must have provided protection from the elements. Deer bones found at these sites have definitely been identified as animals that were killed in the winter. Additional evidence comes from etchings made in the sides of the soft sandstone walls of these caves. Pictures of buffalo illustrate a life of nomadic people, tribes that would head west into Iowa and southern Minnesota to hunt buffalo and then return to the fertile Wisconsin river valleys for the winter.

The presence of abstract art on some cave walls suggests that these spaces may have been used in summer for ceremonial purposes such as a youth's "vision quest" or part of a rite of passage.

Archaeologists have also found a cave with a drawing of a human figure with zigzag lines coming from his head. It is thought this is a picture of a storyteller, perhaps recounting the buffalo hunt depicted on the other side of the cave.

Adventure seekers

Maybe we've piqued your interest to start exploring caves in your area. Like many other outdoor sports you should do your homework before you go. Start by getting in shape, getting some training and exploring well-established, larger caves in the company of experienced cavers. Know where you are going, find out if you need permission, tell someone where you are going, take along plenty of water, flashlights, a helmet – anything you need to be safe. It has been a while since Wisconsin has had someone lost in a cave, so make sure you aren't the next.

Dos and don'ts

The cardinal rule is: never explore a cave alone. The minimum size of a caving group as recommend by the Wisconsin Speleological Society is four. The logic is that if one person gets hurt, one can remain with the victim while the other two go for help, with one of those two returning with emergency supplies while the other waits for rescue personnel. Even if you are with a larger group, don't go off on your own. And make sure you have left explicit directions as to where you are going and when you expect to return.

Next you will want to bring light. This can be in the form of a head light, flashlight or carbide light.

Go slowly. Remember that hiking and climbing can be strenuous. You should also be aware that you can chill quickly. Be prepared. Spelunking is usually a dirty and rugged venture, so consider head protection, gloves, knee pads and a light jacket. When your adventure is over, you will likely want a change of clothes.

What if something goes wrong? If you find yourself lost in a cave, just sit down and wait. Soon people will start to look for you. Wandering around a cave will only make rescue more difficult for everyone involved.

Another consideration is bat droppings. Many of these caves are also home to bats. The feces of bats often contain salmonella, a bacteria that can affect humans. Make sure you wash your hands and face before eating and be aware that the bacteria might also be on your clothes. Don't wash your hands and then dry them on your pants.

Be respectful of cave walls that protect both natural and cultural treasures. Do not touch or write on cave walls. Don't ruin the experience for those who will come after you. The same is true of garbage. Pack out absolutely everything that you pack in.

Also, never ever take cave formations home and never touch any of these ancient art forms. If you find broken speleothems, leave them where they are and report them to archaeologists. These structures have taken centuries to form and can provide important information to historians and scientists.

Never collect wild plants and animals from caves. Because these sites are such a rare habitat, these creatures may only exist in small numbers. Taking moths, bats, reptiles, etc., out of these caves could have disastrous effects on their populations.

And finally, bring common sense. Avoid drugs and alcohol. Caves can be dangerous enough without adding stupidity. Stick together as a group. Avoid playing pranks.

Public limestone caves

The best places to experience caves for the first time are the caves open to the public. After you've experienced these, you can join the Wisconsin Speleological Society to learn about more "wild" caves. Here are some of the best known public caves.

Cave of the Mounds, Blue Mounds

Of the caves in Wisconsin, perhaps the best known is Cave of the Mounds near Blue Mounds in South Central Wisconsin. This cave was discovered in 1939 by workers quarrying limestone. A large blast unearthed an underground cavern. The initial opening was more than 20 feet high and led into other rooms. Soon word got out and people started to travel to see the great cavern. Soon thereafter, in 1940 lights and walkways were installed and it was opened to the public. The main cavern is believed to be over 400 million years old and was shaped over the years by acidic water and dissolved limestone. Visit Cave of the Mounds or call (608) 437-3038.

Crystal Cave, Spring Valley

According to the history books, Crystal Cave was discovered in Spring Valley in 1881 by a local farm boy, William R. Vanasse. The discovery occurred while William was walking through the woods just a short distance from his home. The 16-year-old, discovering a small leaf-filled sink, probed and pushed with a stick which suddenly slipped from his grasp, disappearing into the ground. Initial exploration of the cave took place the next day when William and his younger brother, George, descended into the large vertical entrance. They entered a clay and debris filled dome from which they then dropped down into what is now the main room of the second of three levels. Over the decades, this cave was excavated exposing larger rooms and caverns. Two details that separate Crystal Cave from the others are that it is home to four bat species, and the limestone and dolomite were deposited one layer at a time giving it a layer cake appearance. The cave is the longest known natural cave in Wisconsin. See Crystal Cave or call 1-800-236-2283.

Kickapoo Indian Caverns, Wauzeka

This limestone cave in Grant County between Boscobel and Prairie du Chien is an exception to the rule in that it was once a Native American shelter. It boasts underground caverns, an underground river, and onyx deposits. It closed to public visits in the 2007 season and may or may not be available for visits into the future. Visit Kickapoo Indian Caverns.

Ledge View Nature Center, Chilton

Ledge View Nature Center in Chilton, Calumet County, is a county park with three caves to tour. Trips are geared to introduce different age groups to caving experiences. The site provides a more "wild" experience because there is no electricity and no concrete along the routes. Stairs and ladders provide access for visitors, but this cave is basically all crawling! The most notable of the three caves, Mother's Cave, is so named because it was found on Mother's Day in 1986. The caves are also home to rare moths, so be sure to tread lightly. See Calumet County or call (920) 849-7094.

Eagle Cave, Blue River

This cave in southwestern Wisconsin (northeastern corner of Grant County, west of Muscoda off Highway 60) was discovered in 1849 by two hunters chasing a bear in winter. The entrance was easy to find and soon others came to the cave. It is considered the state's largest onyx cave with several large rooms and formations. In 1937 local businessmen got permission to open the cave as the first public cave attraction in Wisconsin. Enthusiasm for the cave still exists in fact several boy and girl scout groups use it for camping as it can accommodate more than 250 in the entrance hall. Contact the cave operators for details. Tours are offered Memorial Day through Labor Day. Eagle Cave, 16320 Cavern Lane, Blue River, WI 53518. Call (608) 537-2988.

Why are people cavers?

Caving is fun for kids and adults alike. Fiske says, "I guess my interest in caving stems from my own family outings as a child. At least once a year, my parents would take our family to a commercial cave for a day. I carried on with that tradition with my own family and took it one step further and got involved in wild caving and exploring non-commercial caves."

There is a whole culture of adults who go caving in Wisconsin not to mention college campus groups like the Wisconsin Hoofers who plan cave explorations.

"The cavers in Wisconsin are a varied group of individuals," says Fiske. "The thing that binds us together is the draw of the unknown, the thrill of exploration, and the knowledge that you may someday stumble on a new discovery that no other human being has seen before. Cave exploration to all of us is comparable to walking on the moon."

Cave exploration has its dark side as well. Rare rock and cave art has unfortunately become the target of would-be thieves and vandals. Late in 2004, a 1,000-year-old rock painting was defaced with spray paint at Roche-A-Cri State Park. Vandals tried to saw out an ancient rock painting at Gottschall rock shelter in Iowa County back in 1994 and just last August, vandals scratched their initials into a cave painting at a historic rock shelter in Larsen Cave near Eastman northeast of Prairie du Chien.

Since 1996, state law set felony penalties of up to 3 years imprisonment and fines of up to $10,000 for damaging antiquities like rock art. Archaeologists across the Midwest work to educate the public about these priceless remnants of past cultures, but are hesitant to describe exact locations for fear of future theft and vandalism. Protecting and patrolling a host of a shelters and sites may be prohibitively expensive. Many caves that provide rare habitat for bats and other animal and plant species just can't preserve those natural features and accommodate human visitation.

One of the three largest bat hibernation sites in North America is an old mine near Iron Ridge in Dodge County, now preserved as the Neda Mine Bat Sanctuary. The old iron mine, abandoned in 1914, was donated to the University of Wisconsin-Milwaukee in 1975. More than four miles of tunnels in the mine maintain a constant 40F temperature year-round and it's home to more than 500,000 bats that migrate here from at least a four-state region. Extensive research takes place here and the site has been protected with gates to keep the curious from disturbing the fragile bat habitat and its winter inhabitants.

Reputable, respectful cavers are part of the solution to human intervention problems. They show people how and where caves can be explored and enjoyed without damaging the natural and cultural treasures in these rare places.

To learn more about caving in Wisconsin, visit Wisconsin Speleological Society and click on "caving links". To read about archaeological sites and research in the southwestern Wisconsin caves, visit Mississippi Valley Archaeological Center, at the University of Wisconsin-La Crosse. Check out the Minnesota Speleological Survey.

Writer Judy Nugent also hosts "Outdoors Radio" with Dan Small and produces feature segments for WMVS-TV's "Outdoor Wisconsin" show.