POSTED: 1:30 a.m. HST, Aug 26, 2013
LAST UPDATED: 2:07 a.m. HST, Aug 26, 2013
RACINE, Minn. » John Ackerman has been called a tree hugger and a kook by two landowners and a devil worshipper by a local town board member. He has been accused of land snatching and gold prospecting. Others see him as an explorer and a fierce protector of an underground wilderness.
"This is what I do - I find a cave and find out where it goes," Ackerman said. "Then I knock on the farmer's door, and of course he's going to shut it.
"You're going to offer him some money, and he's going to say, 'Why would I want to sell you 1 acre or 10 acres in the middle of my property?'"
Then, Ackerman said, he sets out trying to persuade farmers to sign away the subterranean rights to their property, often for tens of thousands of dollars an acre.
Since the mid-1980s, Ackerman has been traveling to southeastern Minnesota from his home in the Twin Cities area to explore and acquire caves. He is the largest private cave owner in Minnesota and might be the largest in the country, but nobody is certain because not all of his caves have been fully explored to determine their extent.
Among his prized holdings is Spring Valley Caverns, located in what he calls the Minnesota Cave Preserve, his subterranean holding of six caves that run collectively over 40 miles.
"There are always passages to find," he said. "I've pretty much explored all of the hot ones and found 5 1/2 miles."
He finds caves by scouting out sinkholes scattered throughout the region. Sinkholes can lead to caves, but the opening is usually plugged with a few thousand years of rocks and sediment. Ackerman has a modified excavator that claws out tons of dirt and rocks as he looks for a gap.
Once open, he crawls in and explores the cave as far as he can. With the help of a partner, he uses a device that beams low-frequency waves to the surface. Above ground, the partner marks the location sent out by the device, a small test hole is drilled and a camera is lowered to confirm they hit a cave passage. Then he hires a well driller to bore a 30-inch hole to the cave.
A ladder is mounted to the side of the hole to climb down into the cave. At the surface, the opening is capped with a corrugated metal tube that has a steel lid. It is padlocked, and only Ackerman has the key.
Such private power over an exclusive natural landscape has earned him enemies and supporters.
Among those who question Ackerman's pursuit is the Minnesota Department of Natural Resources.
"When I started opening up miles and miles of cave, they started looking at that and they weren't real happy," Ackerman said. "But I've constantly reminded them I'm protecting them and I'm allowing scientists to study them."
Indeed, he permits groups from elementary schools as well as university researchers to visit the caves. Exploration has unearthed fossils and rocks that have drawn the interest of scientists.
Ackerman grew up in Burnsville, Minn., and he developed an interest in caving by exploring abandoned sand mine tunnels under St. Paul as a boy. He runs a successful furniture restoration business that he started in his garage, which has been able to finance his pursuit of caves.
The 59-year-old Ackerman says he is at a time in his life where some decisions will have to be made about his caves. His three children are now adults and not particularly interested in inheriting them, he said, and he and his wife divorced three years ago.
"So who am I going to donate them to? I don't know yet," he said. "I've always said from the very first day I'm just a temporary steward of these caves.
"Who can own the cave anyway? These caves are a million years old. It's just a position I've gotten myself into."
He says he is apprehensive about a government agency taking over the caves and barring access, or worse, it becoming a commercialized roadside spectacle.
Ackerman contacted the Minnesota Land Trust, a nonprofit group that specializes in conservation, to explore his options. But three years ago, Ackerman had a revelation in the middle of the night, and he said he knew exactly what to do.
"I established a formal cemetery above the biggest room in this section of the cave where they would take tours," Ackerman said, referring derisively to the possibility of visitors to the caves after his death. "That's where I'm going to be buried. So now, let's see them conduct tours over my dead body."