Greg Brick stepped off the side of a path and bushwhacked down a steep bluff above the Mississippi River, grabbing tree branches for support as he listened for the sound of running water.

He was looking for a burbling spring that once promised healing waters.

It was here, near the former Pillsbury A Mill in Minneapolis, where a resort catered to 19th-century tourists who wanted to drink iron-bearing “medicinal” waters flowing out of the river bluff.

It’s not the only once-famous, now-forgotten spring that Brick knows about.

There’s the spring, hidden behind an apartment building in St. Paul’s Highland Park area, that once supplied a thriving business that bottled and trucked fresh water for thirsty city residents through the first half of the 20th century. Or the spring, discovered in a rock face in Minneapolis’ Seward riverfront, which was described in a 1977 front-page article in this newspaper as a “fountain of youth” and a cure for hangovers.

The springs haven’t gone anywhere. You can still see them, if you know where to look, quietly flowing as they have for hundreds of years.

But Brick knows their secrets. He’s a spring hunter.

The 54-year-old caver, urban explorer, writer and historian from St. Paul has been finding, studying and mapping long-lost springs in the Twin Cities area since he was a college student in the 1990s.

Now he has a job looking for springs statewide as a research analyst working on the Minnesota Department of Natural Resources’ spring inventory project.

Minnesota, the Land of 10,000 Lakes, is also likely the land of more than 10,000 springs. But no one really knows for sure because there’s never been a comprehensive statewide effort to find and catalog the state’s springs.

But starting in 2014, using $370,000 from the Minnesota Environment and Natural Resources Trust Fund, the DNR has been finding Minnesota’s hidden or long lost springs and creating an online database of their locations. Part of the money was used to hire Brick to be the state’s full-time spring hunter.

Geologist and nerd

Brick is uniquely suited for the job. With a doctorate in geology, he’s an intrepid nerd, combining a long fascination with the world beneath our feet and a willingness to do the hard and sometimes dirty work to investigate its mysteries.

In 2009 he published a book, “Subterranean Twin Cities,” documenting his two decades of unofficial exploration of the tunnels, caves, sewers and underground waterways of St. Paul and Minneapolis. His adventures included plenty of encounters with bats, rats, mud and sewage.

Looking for springs has its own perils. They’re often hidden in rough terrain, on steep slopes or in remote swampy areas of parks where there are no trails.

“It’s kind of a mix of historical research and sheer grunt work,” Brick said. “It’s a lot of up and down work. The springs tend to occur in very inconvenient places.”

Brick said he’s gotten stuck on rock ledges and slipped and rolled down steep bluffs a few times while on the hunt. Now he carries a length of nylon rope to help haul himself up slippery inclines while searching. He often finds a handhold thanks to a sturdy nuisance plant that seems to thrive on steep riverbanks.

“Buckthorn is an abhorrent invasive, but it’s the tree of life for the spring hunter,” Brick said.

He has a flotation coat that he can wear if he’s trying to find a spring near lake ice. “There are some things I’ve been forbidden to do, like going out on ice shelves,” he said. “I don’t do that anymore.”

If you spend time in Brick’s DNR van and listen to him talk, you’ll get a picture of a man nearly obsessed about springs and nearly immune to the discomforts in finding them.

He will spend three or four days at a time in the field, roaming through outstate Minnesota in all kinds of weather, often trekking to unvisited parts of parks to find a spring that is unlikely to ever see another visitor. He catalogs his finds on the spot in a special tablet that uploads his data.

“I get way, way off the trail system,” he said. “In doing this work, you get to see the parts of the state park system that no one else does.”

He recently started a YouTube channel, documenting his exploration around the state of boiling springs, sulfur springs, gas springs and a spring named after King Kong. There is also a video he created from a vacation to Las Vegas with his wife. It’s of a spring, now dried up, that originally put Las Vegas on the map.

Brick uses everything from laser-scanned topographic images to old newspaper clippings to find springs.

But oftentimes, he’s just trying to notice a subtle change in the landscape, a different shade of green, that will reveal where a spring is hiding.

“Sometimes a spring announces itself just because something is out of place,” he said. “It can be frustrating if you can’t think like a spring.”

From caves to campuses

Brick has been looking for springs since the early 1990s, when he learned there wasn’t a good database of them in the Twin Cities. As a University of Minnesota undergraduate, he decided to create one as a research project.

That led to the publication of a 1997 article in the Minnesota Ground Water Association newsletter describing his adventures tracking down springs such as “St. Paul’s diamond necklace,” an 8-mile loop of two dozen springs beginning near the St. Paul Cathedral and heading through Highland Park and all the way up to the Town & Country Club golf course in Merriam Park.

“Those springs of that magnitude were not on any map,” Brick said.

He also found springs in caves, in residential basements and on college campuses. Take the spring-fed Dew Drop Pond at St. Catherine University, which Brick describes as having “the melancholy distinction of being the only local spring in which people have drowned.”

“It was in the St. Paul paper. It was like some lovelorn lassie just drowned herself,” Brick said. “I suppose like Ophelia in Shakespeare. Although I’m not sure that was a spring.”

Another spring he’s investigated is located in the shadow of the Mall of America. Brick said some people have mistakenly thought the water was draining from the mall’s Sea Life Minnesota Aquarium. In reality, the spring is the headwaters of a trout stream. “They don’t see it as a spring. They see it as a nuisance,” he said of the reaction many people have to water that comes out of the ground instead of a faucet.

Renewed resource

Springs were better known — and more highly valued — a century ago.

Some of the springs Brick has rediscovered were important sources of drinking water for Minnesota towns such as Jasper or Grand Marais. Or they were believed to have medicinal properties, such as the sulfur springs of Jordan, source of Mudbaden spa, which in the early 20th century touted mud bath treatments for rheumatism, high blood pressure, liver disease and gout.

As late as the 1970s, the Minneapolis Park Board allowed the construction of a path to the Hajduk Spring, on the Mississippi River near E. 24th Street, to allow people to fill jugs with spring water coming out of the top of the riverbank. The spring was discovered by a man named Harry Hajduk Sr., who regularly drank the water and lived to age 97.

But springs were largely forgotten as municipal water systems turned to lake, river or well water, and belief in the healing properties of springs faded.

The path to the Hajduk spring has fallen into ruin. Besides, Brick said, he wouldn’t drink from it now considering the herbicides or fertilizers that might be spread on the residential lawns above the spring.

“Just getting down there is a real pain in the neck nowadays,” he said.

Still, springs have natural and cultural value.

“They’re lovely to look at,” said Jeff Green, a DNR hydrogeologist in Rochester who was an early champion of the spring water inventory project. “I do this for a living, and I find them mesmerizing.”

Springs supply wetlands and provide the cold water that feeds trout streams and cool-water fisheries. They can give researchers a window into the health of our groundwater. They support unusual, endangered or threatened plant and animal life, such as certain dragonfly species that live only around springs.

“They’re little islands of unique habitats,” said Ronald Lawrenz, director of the Warner Nature Center in Marine on St. Croix.

But springs also need to be watched for the problems they can cause, creating landslides, washing out trails or icing up road surfaces.

The sound of running water when the rest of the world here is frozen is often a clue that a spring is nearby because spring water comes out of the ground year-round at a constant temperature of about 47 degrees. That creates a thermal oasis around them, a little pocket of spring even on the coldest days.

Many of the spring ponds that Brick has encountered are filled with watercress. Constantly bathed by warm water, they’re a patch of living green in the middle of the winter. Brick said Hmong Minnesotans often harvest the aquatic plant.

“It’s supposed to be great in salads,” he said.

Open waters created by springs are midwinter habitats for ducks or trumpeter swans. Brick has seen robins in winter near springs, and frogs that keep warm by staying in caves warmed by springs.

“It’s like a thermal spa to them,” Brick said.

But spring water seems cold in the middle of summer. Other creatures have taken advantage of that.

Soldiers building Fort Snelling in the early part of the 19th century lived in what they called Camp Coldwater. In the summer, they preferred drinking the cool water from the spring there, also considered sacred to some American Indians, rather than the warm water from the river.

In his hunts, Brick has also found remnants of spring houses. These are stone structures, sometimes rather elaborate, that were built to capture the chill from spring water. They were used as an early form of refrigeration.

“Minnesotans clearly, clearly love their springs,” Green said. He said creating a spring inventory is an important first step in preserving them. “You can’t protect something, you can’t manage something, if you don’t know it exists.”