Minnesota slackliners test balance (and gravity) high above Lake Superior

Imagine trying to balance in the air a few feet off the ground while standing on a shaky, skinny nylon line stretched between a couple of trees in your backyard.

Just thinking about it probably makes you feel a little wobbly.

Now imagine if that line were two football fields long and suspended between two cliffs more than 100 feet above Lake Superior.

Mark McKee doesn't have to imagine. The 29-year-old Minneapolis man has done it. It's called slacklining, a niche sport that's getting its footing in the Twin Cities area and around the state.

"It's very scary at first," he said of being on a high slackline. "It's very nerve-racking. Your palms are sweating."

Slacklining resembles tightrope walking, except that instead of walking on a rigid, tensioned high wire, you're trying to balance on a length of flat nylon webbing an inch or two wide. And that webbing has stretch and bounce.

Unlike tightrope walkers, slackliners don't use a pole for balance. But on high slacklines, they do wear a climbing harness and a safety leash to catch them if they fall.

Over time, the activity has become more mainstream with affordable starter slackline kits that are easy for anyone to set up and try in the backyard.

It's also become more extreme, with vertiginous slacklining stunts attempted between tall buildings, using hot air balloons or crossing mountain gorges using lines hundreds of feet long, thousands of feet above the ground.

Nothing quite that intense has been attempted in Minnesota, but local slackliners are doing their best to push the envelope.

"In Minnesota, the geography presents its limitations, but we're working on it," said McKee, the organizer of a Facebook group called MINNSLACK.

This summer, a small group of slackliners has been rigging a line above Lake Superior between the cliffs at Palisade Head at Tettegouche State Park on the North Shore.

"The key words are longer and higher," said McKee, who someday would like to rig a slackline on the Mississippi River bluffs in the Twin Cities and walk above the river from bank to bank.

McKee, who has also lived in Utah and has slacklined around the country, is a masonry contractor who started slacklining in 2010.

When he moved back to Minnesota in 2013, he started MINNSLACK to foster interest in the sport and arrange outings. The group has about 300 members. McKee also started a podcast about slacklining in North America (minnslack.com/webslackline).

Much of what MINNSLACK does is less extreme than defying gravity above Lake Superior. They usually meet a couple of times a week to slackline between trees in local parks or around the Chain of Lakes in Minneapolis.

A favorite spot is off Theodore Wirth Parkway in north Minneapolis in an open park field with a bowl-shaped depression that's too hilly for soccer and doesn't get much foot traffic. The lines they rig there aren't very high, but can be up to 750 feet long.

McKee said MINNSLACK members are aware that they're on public property.

"It's an unfamiliar thing for folks," he said. "We do our best to be good stewards of the activity and do our best to answer questions." And, of course, to encourage others to join the group.

The common first reaction for people who try it: "I'll never be able to do this." But McKee insists that almost anyone can walk on a slackline. The main requirement is persistence.

"Your greatest barrier to success on a line is your mental state," he said.

For the first couple of years, McKee said, he practiced on lines 2 to 5 feet off the ground. It took him an hour every day for two weeks before he could walk 30 feet.

Enthusiasts compare slacklining to everything from meditation to flying.

"It lets you kind of escape from everything else because it requires that deep meditative focus," said Hunter Cottrell, a college student and slackliner from Forest Lake.

"I like the feeling of being in the air," said Meridith Graham, a 26-year-old St. Paul woman who likes to do "tricklining," which is bouncing on a slackline like a sort of skinny trampoline.

Typically done in bare feet, Minnesota slackliners continue their sport in the winter using neoprene footwear. McKee said that his group would like to find practice space indoors and that they're always looking for interesting new outdoor locations.

"Any two elevated points 100 to about 2,500 feet apart are of interest to us," he said.

A highline actually consists of two lines, separately anchored. A person walking on the line has to wear a climbing harness tied to a 4-foot-long leash with double lines. The leash is connected to the slackline so that in case of a fall, the slackliner will drop only a few feet before being caught. The lines are capable of holding at least four times the load they are expected to experience.

The leash is connected to the slackline with a drop forged steel ring that slides along the line and is capable of supporting at least 10,000 pounds before breaking. Folks actually use two of the rings at the same time to be doubly sure.

Despite how dangerous it looks, there have been only a handful of slackline-related fatalities, according to a 2016 report from the International Slackline Association. The group said the only highlining death occurred in 2011 in Slovenia and was caused by inappropriate use of equipment.

Done correctly, highlining is "the safest 'extreme sport' you'll find," McKee said.

Safe perhaps, but not necessarily easy.

"If everything is gravy, you can stroll right across," McKee said.

Other times, he has spent a frustrating hour on the line, falling 30 or 40 times, having to climb back on the line each time before finally getting across.

He said so far no slackliner has crossed the Palisade span without falling at least once. Members of his group hope to try it again in October.

"You kind of feel like you're in the middle of nowhere," Cottrell said of the high slackline above Lake Superior.

"It's kind of enjoyable because no one's ever been there before."