Notes From Underground

Tony Nelson

Standing atop a grit-coated concrete platform some 90 feet beneath downtown Minneapolis, Greg Brick shines his flashlight into the blackness. It's a grim scene. To his left, a flaccid condom dangles from a corroded protuberance on the tunnel wall. "Must have been an overflow," Brick cracks dryly. He then directs the light beam beyond the edge of the platform into a fast-moving subterranean river that, at high tide, carried the condom to its current perch. Beneath us, there is a small waterfall, where a metal ladder extends down into gray, translucent fluid; the raw product of innumerable toilets flushing from Brooklyn Park to the IDS Tower.

On city maps, this significant stretch of sewer is called the North Minneapolis Tunnel. Among those who explore the Twin Cities' nether regions, however, the NMT has a host of nicknames, including the Raging River, the Roaring River, and the Death Hole. "To me, that's dumb and uninspired," say Brick of the menacing monikers. The pet name he prefers pays homage to the tiny, shredded strands of toilet paper that line the walls of the tunnel and make it extremely slippery for anyone who ventures into the foul water. "The Silk Road," he says. "That has a better sound." Brick likes to engage in irony now and then. The sewers will do that to a person.

Accompanied by Brick's regular exploring partner, John--a lanky 31-year-old who prefers not to use his last name because he works in private security--we arrived at the NMT easily enough: Armed with no special gear aside from a few extra flashlights and gloves, we first meet at the Stone Arch Bridge on the downtown side of the Mississippi River. After waiting for a passing police car to disappear, we scamper along a rugged embankment through a construction zone, then duck through a cavernous opening in the hillside. Hopping into waist-deep water, wearing just our street clothes, we begin trudging through the storm sewer.

At first our excursion is, while not pleasant, not disgusting. There is the occasional whiff of a disturbing sanitary odor. Brick assures me, though, that the water is reasonably clean. For decades, he explains, the Minneapolis Public Works Department has been working to separate the storm-sewer system, which drains rain and groundwater into the river, from the sanitary-sewer system, which carries more noxious excrement to the Metro Wastewater Treatment Plant in St. Paul. The storm and sanitary sewers do occasionally come together, however; in periods of heavy rain, water will leak into the sanitary sewer, which can then overflow into the storm sewer (and then, sadly, into the Mississippi River). The spot where we spy the dangling condom is one place where this has happened.

Here at the concrete platform, the sanitary fluids don't smell like shit, per se. But they don't smell any better. I try breathing through my mouth. It doesn't help. I feel a queasy twinge. The research I've done into Brick's past trips down the Silk Road don't help either. On three other occasions, he has endured vomiting and diarrhea for up to 48 hours after coming into contact with the NMT's water. True to form, Brick has coined a couple of terms for the affliction: the self-explanatory Tunnel Fever; and the more obscure Rinker's Revenge, a backhanded homage to the city engineer who designed the NMT in the late 19th Century. I ask Brick whether, just by breathing the air, I am in danger of contracting Tunnel Fever. He says as long as I stay out of the rushing water I'll be fine. He then assures me that we aren't going to be doing any major "sanitary work" today.

This is a prospecting mission. Brick is looking for a new connection between the storm sewer and the NMT, which could provide him with a new means to reach one of the Twin Cities' most forbidding underground voids. The size of a half a city block, Schiek's Cave lies in a maze of sandstone some 75 feet underneath Schiek's Palace Royale, a down- town strip club. If one has sway with the public works department, there is an easier and far less hazardous way to access the cave, via a manhole near the intersection of Fourth Street and Marquette Avenue. But Brick is determined to find a route that won't require a blessing from officialdom. And that means locating a new access point upstream. "It's like Murphy's Law. If there's an interesting cave, you can be sure you have to go through some sanitary to get there," he explains. "All you need is an intestinal tract and the ability to puke your guts out, and you're ready to go."


Brick has been exploring, mapping, and researching the Twin Cities' subterranean voids for the better part of 12 years. The 38-year-old St. Paul native had no particular interest in the underground as a child. He admits to always being a curious sort, however--a "proverbial pocket-protector-wearing nerd." By the time he'd enrolled at Cretin, a private St. Paul high school, Brick was spending most of his time with books by 19th-century authors such as Arthur Schopenhauer, a philosopher known for being particularly pessimistic.  

But it wasn't until 1987, when Brick was pursuing an undergraduate degree in biology at the University of Minnesota, that he stumbled across the book that would inspire his greatest passion: Horace Hovey's 1882 caving classic, Celebrated American Caverns. Hovey, a Presbyterian minister and geologist, was famous for his explorations of Kentucky's legendary Mammoth Cave, which features more than 300 miles of passageways, breathtaking limestone formations, and underground rivers. "Hovey was the great figure of 19th-century speleology," Brick explains. "He described things interestingly--wrote about caves that exhale music and sunlight. After reading him, I just thought, there's something I'd like to try."

In short order, Brick began visiting some of the state's best-known subterranean spots, including Mystery Cave, a 12-mile maze of corridors dotted with stalactites and stalagmites in southeastern Minnesota. But while Brick had the caving bug, he also had a problem: no reliable car and a dislike for long trips to prime caving country. So he began exploring manmade spaces in the metro area: everything from storm sewers to old brewery caves to the vast network of steam tunnels underneath the University of Minnesota. Since some of his favorite spots were located in the old milling district near St. Anthony Falls, he rented a cockroach-infested apartment in the neighborhood.

After getting a degree in biology from the U, Brick began taking geology classes. He then enrolled in a master's-level geology program at the University of Connecticut and stayed for two and a half years (Brick wound up spending nearly 18 years in pursuit of a higher education). While there, Brick read The Mole People, a book by Jennifer Toth about the denizens of Manhattan's vast network of underground spaces. Brick and a friend took trips to New York City and made several forays into the city's underworld. As it turned out, Toth's book proved to be an imperfect guide. "There was a lot of truth in it, but there was a lot of bullshit mixed in," Brick says. He was able to locate a few notable subterranean landmarks, however, where he remembers treading over "carpets of crack vials." He also had his one and only run-in with the law, when a subway cop wrote up a trespassing citation. "Somehow, I never did manage to pay that ticket," he says.

Brick's affinity for the urban underground sets him apart from traditional cavers, who spend most of their time in country settings, exploring natural spaces. Most of them shun storm sewers and recoil at the prospect of sanitary work. Brick says his peers' distinctions are specious. "The natural caves are all full of animal shit," he observes. "It's just a question of what type of shit you're rolling around in. And it's a matter of dealing with it to get where you need to go. To me, it's just not a big deal." He also points out that while those who explore natural caves may not get Tunnel Fever, they do run the risk of contracting serious illnesses such as rabies and histoplasmosis.

Whether it's done in a natural setting or beneath a strip club, spelunking remains an obscure pursuit. The largest national organization for cavers, the National Speleological Society, boasts a membership of just 12,000 people. The Minnesota Speleological Survey, which is based in the Twin Cities, is lucky to have 20 people at a monthly meeting. "Most people don't go caving, because they think it's scary and dangerous," notes Calvin Alexander, a longtime member of the MSS and a professor in the U of M's geology department.

Still, for those who do cave, the passion runs deep. One member of the MSS purchased more than 300 acres in southeastern Minnesota, just so he could explore a vast network of natural caverns. Many others will spend every weekend for months attempting to find passages into voids that may or may not even exist. And most cavers, Alexander theorizes, are driven by a common impulse: "Most of the mountains have been climbed. The poles have been reached. Caving is one of the few activities left on Earth where, if you are serious, you have a good chance of seeing something that no one has ever seen before--and knowing that you are the first person to see it."

After his stint at UConn, Greg Brick returned to the Twin Cities in the mid-Nineties, more determined than ever to explore Schiek's Cave, a place that very few people had ever been. On and off since then, Brick has systematically explored downtown's storm sewers, looking for a way in. Then in 1999, Brick contacted Peter Sand, a college student who had been making forays into the city's sewers and posting the accounts on a Web site called the Minneapolis Drain Archives ( Sand, Brick discovered, shared his goal.  

Soon, Brick and Sand were out prospecting for access to the North Minneapolis Tunnel that would put them in proximity to the cave. That summer, they pinpointed a manhole in the Warehouse District. Satisfied, Brick went home to map out a detailed trip. Late that same night, Sand and three friends made their way to the NMT and, in a harrowing act of either derring-do or simple foolishness, entered the raw sewage, waded a few blocks downstream, and then rode the current down a steep drop. Eventually, the three reached a shaft that led them to Schiek's Cave. One of the three swallowed a mouthful of sewage.

Brick decided he would try to emulate the adventure. After going down the same manhole three weeks later, however, Brick and his longtime sewering companion John were alarmed to see that NMT's flow had increased. "I just started feeling so fucking weird," Brick remembers. "Then John looked at me, and he said, 'Let's get out of here.' He said it. But I probably would have if he hadn't. We just hightailed out of there." It was a bitter setback. "I just steamed about it all winter," Brick says now. "It was like I'd been shown up by some greenhorn."

In May of 2000, Brick, still determined to find an alternate route, located a breach in the wall of one of downtown's deep storm sewers. Climbing through the hole, he discovered an access point to a stretch of the NMT that was in close proximity to Schiek's Cave and downstream from the turbulent rapids where Sand had entered. Fearful of contracting a case of Tunnel Fever, he and John donned respirators and rubber waders before entering the waist-deep sewage, then carefully crept to a shaft that eventually led to the cave.

After poking around the cave, Brick was surprised to find the floor of the cavern littered with soda straws and feminine hygiene products. Apparently, a sewer line from Schiek's Palace Royale had ruptured. Brick also began to develop a theory about the cave's origins, which has long been the subject of debate. After examining assorted features, he concluded that it was neither manmade nor natural, but anthropogenic, meaning it was created as an unintended consequence of human activity. Specifically, Brick surmised, the excavation of the NMT in the late 19th Century had changed the groundwater flow, which would soften and ultimately erode the sandstone, creating the cave. Brick hoped further explorations might reveal the presence of other anthropogenic spaces nearby. But his "easy" access to Schiek's proved short-lived. Not long after he and John videotaped a second visit, the city's Public Works crews bricked up the sewer-wall hole that Brick had passed through to gain access to the NMT.

When I first hook up with Brick and John, they are looking for a new opening to the NMT. After inspecting the concrete overflow platform, Brick decides we should travel further up the deep storm sewer. Eventually we head south, traveling beneath Nicollet Mall. As we trudge through the water, the tunnel seems to shrink, owing to an accumulation of sediment on the floor. Soon, we are hunchbacked. It is uncomfortable, especially for Brick, who recently sprained his ankle in a caving accident. Here and there, he pauses to examine some subtle change in what, to him, is a familiar landscape. A small access panel on the side of the tunnel arouses his curiosity. "Maybe I'd fit through, but not fit back," he jokes. "They say you swell up when you get panicked."

At the corner of Seventh and Nicollet, where the intersection is marked with a brass plaque for the convenience of sewer workers, I notice a sudden change in conditions. The air and water have become noticeably warmer. It smells. My glasses fog up. Suddenly, roaches are scrambling helter-skelter. We are in sewage.

For Brick, this is a good sign: a break in the sanitary tunnel could mean a new cave is forming in the sandstone. He takes out his clipboard and makes a notation. Something to check out on another excursion. Something to add to the research. After reaching 12th and Nicollet, we retrace our steps and emerge back on the banks of the Mississippi River. We have been exploring for four hours. The afternoon sun is impossibly bright, a bath irresistibly tempting.


Over the past decade, Brick has published scads of papers in various historical and speleological journals, including "Sanitary Abyss: The Schiek's Cave Adventure," "Lonely Quest: The Exploration of the Fort Road Labyrinth," and "The Skeptical Caver, or Six Years at Chute's Cave." The Schiek's article begins with a sly quote from Goethe's Faust: "Take counsel, cherish not the sun and stars. Come, follow me down into the realm of gloom." His pieces are also laced with linguistic flourishes. In a short piece about the Banholzer Brewery Cave in St. Paul, Brick describes a notable aperture in the cave wall as "a vulviform erosional modification of a vertical joint"--a more discreet variation, he explains later, of "pussy hole," the slang term some cavers use to describe the landmark. The playful tone notwithstanding, Brick's articles are meticulously detailed. "Greg is a very serious researcher, and, from my perspective, one of the most valuable things he does is put things down in writing," observes Calvin Alexander, who was one of Brick's professors at the U of M.

Among members of the Minnesota Speleological Survey, Brick's inner-city exploits are regarded with a mixture of awe and revulsion. When Brick presented a video and lecture on a trip to Schiek's Cave at a meeting of the MSS, his fellow cavers were dumbfounded. "There was admiration for the success. There was amazement," Alexander says. "And there was a lot of, 'No way in hell would I do that.'" Dave Gerboth, another veteran caver, is one of the MSS members who has been willing to accompany Brick in his urban explorations. Once, Gerboth remembers, Brick took him on a five-mile tour through St. Paul's storm sewers. Another time, he led him to a cave under the old Landmark Brewery that required "quite a lot of sanitary." "That was a little bit too much for me. I don't think I want to do that kind of trip again," Gerboth says. "He has a tolerance for pain that I don't have."

Not surprisingly, city officials frown on excursions into the sanitary sewers. Rick Rakow, a foreman with the Minneapolis sewer department, was shocked when he learned of Peter Sand's trip down the NMT and is quick to warn of the risks. "That was extremely dangerous, and they should have never done that. They could have died," says Rakow. While city workers venture into the sewers on a daily basis, Rakow explains, there are a host of dangers. In the sanitary system, decaying feces and vegetable matter produce both methane and hydrogen sulfide, gases which, in sufficient doses, can be fatal. "You can go in there, and the air will be perfectly normal. But as soon as you step into the water, you stir that stuff up. The gas is released, it displaces the oxygen, and then you don't have a prayer." In recent years, the department has become more reliant on remote cameras for their inspections. When repairs need to be made, workers typically bring hydrogen-sulfide and carbon-monoxide sensors.

Brick, who insists he is vigilant about air quality, acknowledges that his adventures can be perilous; his closest brush came a few years back, when he and a companion were prospecting for a sewer entry. They came across a manhole covered by a 200-pound, hexagonal lid. "Whenever you see one of those big lids, you know there's some goodies down there, a big chamber or void," he explains. After prying the lid open with a claw hammer, Brick began his descent into the deep shaft. Partway down, the old metal ladder rungs began to crumble. Just as he was preparing to resurface, his companion dropped the lid. It crashed to the bottom of the pit, hitting Brick's shoulder along the way and nearly taking him down with it.


After our journey through the NMT, Brick and I plan a trip to Satan's Cave on Nicollet Island. The name is irresistible. At least to me. It is just four days after the terrorist attacks of September 11, and our planned entry point is just across the river from the Federal Reserve Bank. John, who is jumpy about doing anything that might arouse suspicion during this tense time, bows out. Brick is less worried but urges a little extra caution on the approach. "That bin Laden is giving cavers a bad name," he complains.

After a rendezvous at the Nicollet Island Inn's parking lot, Brick discreetly leads me to an open manhole by the river's edge and we quickly descend into a small pit. At first it appears we are in a dead-end chamber, but Brick shoves aside a hunk of fallen rock to a reveal a small opening. He plunges into the void headfirst. Unlike our trip under downtown, this feels less like hiking through sewage and more like spelunking. After belly-crawling our way through a few tight passages, Brick leads the way to a long, egg-shaped, brick-lined tunnel that, for the most part, is dry. We walk, bent over, until we reach the north end of the island. We slither through a tight hole and find ourselves in Satan's Cave.  

The sandstone chamber is roomy enough, with a ten-foot ceiling. And by the looks of it, Satan's minions like to party. The space, which was once used for growing commercial mushrooms, is littered with empty beer cans. Still, Brick acknowledges, it doesn't quite live up to its name or its legend: "If I ask people if they want to come with me and walk through some old tunnels, it's, 'I'll pass.' But if you say, 'You wanna go to Satan's Cave?' people will say, 'Cool, let's go!'" On the far wall, three devil heads have been carved in the sandstone and hold votive candles in their mouths. Brick lights the candles. I sit down. It is pleasantly cool, and the floor of the cave is covered with fine, white sand--worthy of a Caribbean Beach. I feel like taking a nap.

In recent years Satan's Cave has attracted not only occasional partiers, but also a new generation of loosely affiliated urban explorers, referred to as the infiltration movement. Unlike Brick and traditional cavers, infiltrators place an emphasis on venturing into forbidden zones for the express purpose of violating the prohibition. "It's almost like a new MTV extreme sport. We call it action squadding," says "Max Action," the 24-year-old founder of an urban adventure group in Minneapolis called the Action Squad. Max, who began exploring storm drains as a kid in Burnsville, has visited a number of Brick's haunts--including Satan's Cave and the U of M's steam tunnels--and posts accounts of the trips on his Web site (

"[Brick's] just very into the historical thing, and he almost scorns the idea of being into this for any thrills or adrenaline, which is important to most of us," Max says. "I like risk. I like getting into places at night where I'm not supposed to be."

"To me, that's just a nuisance," Brick counters. "The difference is between people who come from a caving background and people who come from a trespassing background. A lot of cave work is boring. You do a prospecting trip, then you come back and you do some digging. You know, that's boring to a lot of these point-and-click kids. They're not willing to put in the back-breaking effort."

But while Brick and Max have a tendency to quibble over motive, they both have come to regard certain underground realms as private preserves. And both worry that outsiders might vandalize caves or attract a police presence or cause the authorities to further restrict access. In Brick's case, this proprietary instinct sometimes leads to direct action.

Not long after our trip to Satan's Cave, Brick leads me to the mouth of the old Heinrich Brewery Cave on the U of M's West Bank, where there is a locked gate. A few years back, he explains, the Department of Natural Resources installed the gate and a lock to protect the eastern pipistrelle, a rare bat that inhabits the cave during winter months. Periodically, visitors to the cave would smash the lock, so Brick decided to replace it himself. "I don't know if it's selfishness or whatever. Maybe I just want the cave to myself," he says. "And it's not the only time it's happened. I guess I just like having my own little keys to the underworld. I know it's not mine. It's not my cave or my sewer tunnel to lock off, but I do it anyway. Isn't that bizarre?"


For our last expedition, Brick has selected the most physically taxing destination yet, a place called Chute's Cave. (Brick is particularly protective of this spot and asks that precise points of entry not be disclosed.) We meet at 11:00 a.m. on a Sunday, not far from an old mill in Minneapolis. Once again, Brick's frequent partner is a no-show. We are accompanied by two other people, however: City Pages photographer Tony Nelson and arts editor Michael Tortorello. Brick has handed me a child's bunk-bed ladder to carry, and he cautions me to be discreet. I have no idea how to be discreet while carrying a bunk-bed ladder on a public street, so I just stick it under my arm. We trundle down the block and no one pays any attention.

To get to the cave, we first hike down to the river, where we wade into the mill. Once out of sight, Brick changes into ratty jeans, old lace-less sneakers, and a light coat. It's a warm day, but Brick has warned us to add layers. The trip to Chute's involves a rugged crawl, and the extra clothes will help prevent bruising. After reaching an inner recess of the mill, Brick puts the ladder in place and one by one we climb up and into a maze of small, connected chambers. Eventually we reach a wall where there is a craggy opening. Waist-high, it is just big enough for a human being to fit through. Nelson has brought along a fair amount of bulky (and expensive) camera gear to photograph the cave. It's clear right away that the tripod will have to stay behind.  

Brick first pioneered this route into Chute's Cave on a solo mission in 1990, which makes him the first person to document a visit in 81 years. Since then he has come back dozens of times. Now and then he brings visitors, but oftentimes they balk at the point of entry. "One guy who accompanied me years ago had been to Vietnam. Once he got up here, he said he thought he might start having flashbacks if he went inside. I don't know if he thought some VC would bayonet him if he went through that crawlway, but he was sweating like a pig."

With Brick leading the way, we pile face-first through the opening. As we belly crawl over the jagged rocks, there are the inevitable birth-canal jokes. In spots, it seems impossibly tight. As a novice, I am astounded that any person in reasonable mental health would pioneer such a route unaccompanied. Heavy limestone rocks loom overhead. My thoughts turn to Floyd Collins, the most famous caver of all time. Collins, a skilled spelunker, was deep within Kentucky's Sand Cave in 1925 when a rock crumbled from the ceiling and pinned him by the foot. Over the next two weeks, he suffered an unimaginably wretched death, as some 20,000 onlookers, journalists, and hapless rescuers watched from above. In death, Collins endured further miseries. His body was initially displayed in a glass coffin as a tourist attraction, only to be stolen and then recovered, minus a leg, in a nearby river. I don't want to be another Floyd Collins. The only thing that keeps me from panic is the knowledge that, as the third person in line, I'm less likely to be blindsided by an unstable skull crusher.

It is, Brick tells us, a 130-foot crawl to the cave proper. I can't tell; the route is like a corkscrew, and I can't see anything more than 10 feet ahead. At the midway point, we come to an elegant, naturally sculpted flowstone formation dubbed the Medusa. There is a constant sound of dripping, and little pools of water have collected on the rock ledges. The dripping water creates formations as it deposits minerals on the rocks. They glisten in varying hues of orange and red. They look soft as pillows.

It is a long, slow haul. Then, one by one, we finally emerge into the most decorated cave in the Twin Cities. On one side of the triangular chamber, there are a half-dozen enormous, decaying wooden pillars that have sunk into the ground and are supporting nothing. The pillars were installed following a partial collapse of the cave in 1881, which also brought down part of the street above. Massive slabs of limestone that came down during the collapse sit in the center and rear of the rotundalike cavern. They are covered in flowstone, which looks like melted wax. Scrambling atop the pile, Brick points out one odd little formation after the next, named for what they look like, not what they are: cave pearls, bacon rinds, fried eggs.

To our left is Chute's Tunnel, which was originally excavated to provide a water supply for the mill. When the workers unexpectedly struck the cave, the tunnel became useless. From 1875 to 1880, an enterprising businessman gave ten-cent tours of Chute's Tunnel in a torchlit flatboat. It was, Brick notes, the state's first commercial cave. Brick, Tortorello, and I try to walk up Chute's Tunnel but quickly became bogged down in a deep, bright-red, gluelike sediment. On a previous trip, Brick made it deep into the passage before sinking waist deep in the muck and losing his shoes. "I had to walk out in my stocking feet," he says, with a hint of pride.

We spend an hour or so in the cave. Nelson takes pictures. Tortorello asks questions. I wander back into a dry and distant recess to lie down on a rock. I turn off my flashlight and the space becomes a sensory-deprivation tank. The whole world disappears.

A day after the Chute's Cave adventure, Brick and I meet at a Perkins. Recently laid off from his job as an environmental geologist, Brick is at loose ends, contemplating a change in career. The field, he explains, is too cyclical, and there are too many folks out there with master's degrees. "It just has the most insidious combination of characteristics," he sighs. "The work is extremely hard to get. It takes six months of looking. And once you get it, the work is boring and doesn't pay more than $30,000 a year. I'd just like to get away from the grind, maybe teach physical sciences at a community college."  

He is thinking about writing a straight-up guidebook to the caves of Iowa for a small regional press. He has also been contemplating his relationship with his fellow explorers. He respects the traditionalists in the MSS and is willing to share information with them freely, although most of them have little interest in exploring underneath the cities. But he worries about guys like Max Action messing up access to his favorite spots. It's not that he has anything against Max per se. He may be the nicest guy in the world, Brick says. And, who knows, maybe he could help with research. After all, it's a struggle to find anyone willing to do sanitary work. "It's just that same old thing," he says with a smile. "They're all weird but me."

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