SACHA PFEIFFER, HOST:
For farmers, spring planting season is about to begin. In Minnesota, though, it's been a long, snowy winter. But that means it's still cold enough to grow an unusual crop. It's ice that people can climb. Dan Kraker of Minnesota Public Radio reports.
BRANDY ARREDONDO: Oh, gosh.
DAN KRAKER, BYLINE: Brandy Arredondo grabs two curved ice axes and warily approaches a frozen cliff face.
ARREDONDO: I'm super nervous. Yeah.
KRAKER: Her friend Juliet had talked her into trying ice climbing for the first time.
JULIET: OK, so hold on to the ice axes, one in each hand.
ARREDONDO: OK.
JULIET: Yes.
ARREDONDO: She swings an axe until it sticks in the glistening sheet of ice. Then she kicks in her crampons, metal spikes on her boots that stick into the ice. She slowly works her way up the vertical wall of ice about 10 feet or so until her hands get too cold to continue.
UNIDENTIFIED PERSON: Should I lower you?
ARREDONDO: Yes.
UNIDENTIFIED PERSON: OK.
JULIET: You did so good.
KRAKER: Back on solid ground, Arredondo says she'd definitely try it again - once her hands warm up.
ARREDONDO: Oh, it was very hard. Yeah, but I enjoyed it. It was fun.
KRAKER: People have climbed here in this abandoned rock quarry in Duluth since the early 1980s on ice that formed when water seeped down the 100-foot-tall cliff. But the natural ice was inconsistent. So over the past couple years, a group of local climbers installed an irrigation system that pumps water to the top of the cliff.
(SOUNDBITE OF SNOW CRUNCHING)
NICK FLEMING: From here all the way to the top, it's underground.
KRAKER: Head ice farmer Nick Fleming points out where volunteers buried a water line by hand along the edge of the quarry.
FLEMING: So that's 1,000 feet of pipe that's all underground.
KRAKER: All this for ice climbing, huh?
FLEMING: All this for ice climbing.
KRAKER: Irrigation heads along the top of the cliff spray water down the rock, which freezes into thick pillars and columns of ice.
(SOUNDBITE OF WATER SPLASHING)
KRAKER: Fleming works 24-hour shifts as a firefighter. When he's off, he's usually here, farming ice with other volunteers or tinkering with the system.
FLEMING: We took what was originally just a partying and dumping area hidden in the woods, and we turned it into a recreational spot for everyone to use.
KRAKER: Most ice climbing is still done on natural ice in the mountain west and northeast, but word of Minnesota's ice parks is getting out.
ERIC BARNARD: Last year, we had multiple groups that came from Texas, North Carolina, Kansas, Nebraska.
KRAKER: Eric Barnard is one of the ice farmers who maintain the Winona Ice Park in southeastern Minnesota on a bluff overlooking the Mississippi River.
BARNARD: I always joke like, running thousands of feet of pipe filled with water in a Minnesota winter - like, what could go wrong, right?
KRAKER: The answer, of course, is plenty. The biggest problem is the lines freezing up.
BARNARD: All you can do is laugh about it. Like, when you're getting sprayed in the face by hundreds of gallons of water a minute and you're soaked and covered in ice, it's really absurd.
KRAKER: The first ice farming system in the country was installed 28 years ago at the Ouray Ice Park in southwestern Colorado. Now four full-time farmers maintain routes that draw more than 20,000 climbers from around the world every year. Executive director Peter O'Neil says he's thrilled to see the growth in ice climbing parks.
PETER O'NEIL: I think that's fantastic, right? I mean, the more people that you can introduce to ice climbing and that discover an outdoor recreational pursuit that they can do in the winter is great.
KRAKER: He says one of the hardest parts about ice climbing is finding a place to do it. Minnesota seems to be addressing that challenge. It now has three city-owned parks featuring volunteer-run ice farming systems. Climbers here say that's more than any other state in the country.
For NPR News, I'm Dan Kraker in Duluth, Minnesota. Transcript provided by NPR, Copyright NPR.