Walk this way: Slacklining growing in popularity

BOULDER, Colo. — Slacklining has achieved the recognition that assures its arrival as an outdoor sport: it has been banned by officials at some of the colleges and parks where the test of balance is popular.

The formerly little-known training technique devised by rock climbers is akin to tightrope walking — except the "rope," usually 1-inch wide nylon webbing, isn't so tight. This means that the line can sway wildly with the slightest misstep.

That's why slackliners normally practice just a few feet off the ground, stringing a line over a grassy stretch between trees. But some of the best and boldest slackliners perform hundreds, even thousands, of feet off the ground on lines anchored to rock walls.

"I thought it was kind of crazy, but it was kind of cool, too," said Kate Vander Wiede, an engineering student at the University of Colorado who saw a slackline set up at a rock climbing gym a couple summers ago. She went back two hours a day for three weeks until she had mastered walking across it without falling.

Wiede slips off her shoes and hops on a slackline strung about waist high between two trees at a public park in Boulder. Her arms outstretched, she walks slowly about a dozen feet in one direction, then delicately turns around and walks back.

"It's almost like meditation. You get on a slackline, all you think about is the next step," Wiede said.

But as slacklining grows in popularity, with clubs popping up from Haverford College in Pennsylvania to Arizona State University, not everyone is taking such a meditative perspective.

Citing safety concerns and possible harm to trees, University of Colorado officials banned slacklining on campus this year after dozens of students started showing up at slacklines strung across campus quads.

"Look, we're not trying to be killjoys here," said CU spokesman Bronson Hilliard. "You simply, as an institution, can't accommodate every single fun thing kids want to do when safety and environmental factors come into play."

Slackliners insist the activity is no more dangerous than skateboarding or bicycling, and that properly attached slacklines, which include pads, don't hurt tree trunks.

"They just shove off what they don't understand," said Scott Rogers, a CU philosophy and engineering senior who sets up regional slacklining events and once crossed a slackline 2,900 feet off the ground in Yosemite National Park in California. Don't worry. He wore a safety harness and was tethered to the line.