Peter Lenz felt a little guilty ice climbing last weekend. The weather was disturbingly nice.

With the sun shining and Pine County temperatures hovering in the mid-30s, it was beautiful out — and chilly enough to keep conditions safe for the Sandstone Ice Festival.

For Lenz, though, it just didn't feel like January, and it sure didn't feel like a normal Minnesota winter. "Ice climbing should be cold," he said.

Sandstone's ice cliffs offer a practical lesson in the problems of climate change and how Minnesotans must increasingly adapt. The cliffs attract climbers and business, but it's getting harder to keep the scene going as winter temperatures moderate.

Ice chunks fly off as climbers ascend, often striking the belayers standing below. Evan Frost | MPR News

Sometimes, it's even impossible.

"We had to cancel [the festival] in 2016," said Lenz, who sits on the board of the Minnesota Climbers Association, which organizes the event. "It was just too warm to make ice. And we had to push it back to the first weekend in January just because of warming temperatures."

The festival, which just completed its 14th year in Sandstone's Robinson Park, used to be held in December. But temperatures proved to be too reliably high.

Ice farms, water lines and hope

A climber wears crampons and holds ice picks while they're lowered from a wall. Evan Frost | MPR News

Ice climbing requires big sections of solid, vertical ice. Climbers wear boots with crampons and carry ice tools, which are like hammers with sharp metal picks on the ends. They use a harness and rope to protect themselves in case they fall.

At Sandstone's Robinson Park, the ice runs down rock walls left behind from an old mining operation. Some of the ice forms naturally; much of it is man-made.

A few years ago, the city ran a water line out toward the park so the climbers group could build an ice farming system. A band of volunteer climbers installed a series of pipes, misting devices and low-flow showerheads to run water down the cliff.

A pipe used to farm ice for climbing sits filled with ice, which caused it to crack open on top of the rock wall. Evan Frost | MPR News

Now, if conditions are right — somewhere around 25 degrees, Lenz said — perfect slabs of ice form from the system.

"It's really dependent on the temperatures, and we've struggled this season already with finding weeks that have those good temperatures," he said. "In December we had to not farm for two weeks just because it was too warm."

The trendline is worrisome for Sandstone and its climbing crew. Historical temperature data show the city's Decembers and Januarys trending several degrees higher over the past 120 years.

Charts: Average temperature in Sandstone for December

December and January

Across the state, winters are getting shorter and warmer, about 1 degree every decade. It's changing ecosystems and affecting economies, especially in outdoor recreation — you can't ski or snowshoe without snow.

James Loveridge, left, helps beginner ice climbers learn the ropes. He is the president of the Minnesota Climbing Association and has been heavily involved in turning sandstone into an ice climbing destination. Evan Frost | MPR News

The ice farming system uses an estimated 65,000 gallons of water each year, said climbers association president James Loveridge. Water use varies depending on the year's weather conditions.

"This year hasn't been that cold, so we probably used a bit more water than we wanted to," Loveridge said.

Sandstone doesn't charge the climbers group for the water, Loveridge said. If it did, he added, the nonprofit couldn't afford the bill on its shoestring budget.

Putting Sandstone 'on the map'

Loveridge gives a lesson on ice climbing. Evan Frost | MPR News

Robinson Park in Sandstone is an hour's drive from Duluth and 90 minutes from the Twin Cities.

As more people get into the sport of climbing, the city is poised to become an even bigger rock and ice destination. It wasn't that long ago when the park had a much different vibe.



In the 1990s, it had a couple picnic shelters and some benches and tables. People used to dump their trash in the park. It was a common site for drug deals and illegal parties.

Some locals just didn't want to go to the park, said former Sandstone city administrator Sam Griffith.

Tony Vavricka started climbing in Robinson Park around 2000. After a couple years, he got the idea to throw an ice-climbing festival and approached city leaders with the idea.

Officials were beginning to realize climbing was happening in the park, but it wasn't exactly permitted. So, the city of Sandstone had a choice.

"They were going to either have to completely ban the climbing or figure out a way to get the insurance to make sure that the city was covered," said Vavricka, who now owns an outdoors guide business in Sandstone.

Sandstone chose the latter and got the proper insurance coverage to allow climbing in Robinson Park.

Many of the routes are man-made, while a few occur naturally. Organizers said this year's Sandstone Ice Festival has the biggest turnout they have ever seen. Evan Frost | MPR News

The climbing community helped revitalize the park, Griffith said, and they'd show up in droves for community clean-up days to pick up trash.

"We would have more climbers show up for community clean up than we did local people and we literally cleaned the park of pop cans, water bottles, garbage, tires, all those kinds of things," he said.

Climbing's popularity is blooming cross Minnesota, especially in the Twin Cities where multiple bouldering gyms have popped up in the past few years.

"Once climbers starts getting comfortable in the gym, it's a natural progression to climb outside climb rock or get involved in ice climbing," Lenz said.

While the sport isn't big enough yet to spur any massive economic growth, Griffith said it's good for Sandstone's notoriety, which is why local leaders hope they can keep it going despite the changing climate.

The ice walls and the people who love them, he said, have "helped put the city on the map."