Slackliners: Hey Boulder, cut us some slack

Prompted by a $250 ticket in July, a group of slackliners is lobbying the city of Boulder to change its laws to allow the sport on public property.

Slacklining, or the use of a narrow, flexible line tied between two trees a few feet off the ground, is illegal under two Boulder ordinances that prohibit attaching devices to public property and trees. Slackliners, or slackers as they're known colloquially, balance on the lines while walking or doing complicated tricks and poses.

After word spread that Tyler Shalvarjian, a University of Colorado junior, got ticketed in Boulder's Martin Park on July 22, some members of the local slackline community decided enough was enough.

Professional slackliner Heather Larsen works her way across a nearly 100-foot long line at Bear Creek Park in Boulder in July.
Professional slackliner Heather Larsen works her way across a nearly 100-foot long line at Bear Creek Park in Boulder in July. (Ryan Gooding / For the Colorado Daily)

They want the city's leaders to consider making the sport legal in town with reasonable rules and regulations to protect trees and ensure the safety of passersby.

"We think slacklining is really beneficial to the community," said Justin Wagers, a professional "trickliner" who graduated from Boulder's Fairview High two years ago. "We leave spots cleaner than they were before, we're always picking up trash and stuff. I really don't see any major reasons slacklining should be illegal."

The city's ordinances used to squash slacklining on public property were designed to keep members of the public safe and to protect trees, said Sarah Huntley, a spokeswoman for the city.


So far this year, police have issued two citations under the ordinance that prohibits attaching materials to city trees. In 2014, police issued eight tickets, up from five in 2013.

Huntley said the city is concerned about someone running into a line they didn't see or someone getting injured while slacklining. The city also takes tree health very seriously, she said.

"Part of the concern is that we would be held somehow responsible for the injury that occurred on public property," Huntley said. "In general, we take public safety very seriously in the city. We're certainly open to discussions about ways to accommodate those concerns, but at the moment it is prohibited in city parks and we would expect people to respect the ordinances that are on the books."

Wagers and Shalvarjian said they use "tree protection" such as a pad or carpet to prevent damage to the bark and always find trees with sturdy, well-established trunks.

They said slackliners stay near their lines at all times and mark them with bright tape or flags to prevent anyone from unknowingly running into them. They avoid high-traffic areas and paths, they said.

Shalvarjian said community-wide discussions about slacklining rules are long overdue.

"It's almost as though nobody has thought out proper rules for slacklining," he said. "We've just slotted slacklining under this random ordinance and haven't really spent the time to figure out proper guidelines. Boulder seems to be a little bit behind the times and also a bit conservative."

—Sarah Kuta, Staff Writer

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Slacklining is hardly as chill as the name may suggest. The acrobatic sport involves stringing a flexible line between two trees or poles a few feet off the ground and attempting to walk across it — or do other crazy daredevil tactics like run, jump or flip on it.

Slackliners can be found doing tricks on the Norlin Quad, But it's also a serious sport. Many slackliners walk the line between canyons and is now part of the summer GoPro Mountain Games in Vail, where athletes butt-bounce, chest-bounce, flip and spin — all while balancing on a 2-inch thick line.

But whether you've never walked a line or are a butt-bouncing champ, you'll need to know the rules for setting up lines, both on campus and in the city. So here they are:

On campus

CU "affiliates" can string lines on campus between sunrise and sunset, as long as they are willing to assume "any and all risk associated with this activity," including "death, paralysis and serious injury." Tricks and stunts are not allowed, according to the CU website.

Lines cannot be longer than 50 feet, must be attached to trees greater than one foot in diameter, cannot be more than four feet off the ground and cannot be within 20 feet of sidewalks, roads, buildings and other campus fixtures. They cannot be attached to anything other than trees and the trees must be protected.

The campus also reserves the right to shut down any slacklining activities or restrict the use of certain trees.

If that's a risk you're willing to take, here are a few other things to consider:


Campus policy states that trees must be larger than one foot in diameter, and that some type of protective fabric must be placed between the slackline and the trees to protect the bark. Trees that have been damaged by slacklining might be restricted for use in the future.

Make sure there's a clear and flat-landing surface below the entire length of the line. You cannot use memorial trees or trees that are otherwise already prohibited for slacklining.


You must tear down your line at the end of every session — all lines are temporary, according to CU policy.

The line may not be higher than four feet in the center, and it cannot exceed 50 feet in length. The center of the line may not be within 20 feet of sidewalks, buildings, roads, streets, bikeways, water features, sport courts, bike racks, handrails, art objects, fences or light poles.

Also, you cannot set up a line within a special event zone. So, yeah, don't try this near a Buffs home game.

University officials who deem equipment to be unsafe or harmful can remove it.


Slackliners are not allowed to be under the influence of drugs or alcohol while participating, and no stunts or tricks are allowed — just walking. So if you're looking to go pro in slacking, think again about practicing on campus.

A spotter is "strongly recommended" according to campus policy.

In the city

There's nothing specific about slacklining in Boulder city code, but two ordinances make it illegal on public property.

Ordinance 6-6-6 c states that "no person shall attach to or install on any tree or plant growing within or upon any City-owned or controlled property, including public rights-of-way, without first having obtained approval from the city manager, any metal material, sign, cable, wire, nail, swing, or other material foreign to the natural structure of the tree, except materials used for standard tree care or maintenance, such as bracing and cabling, installed by tree professionals."

If that's not enough, ordinance 8-2-16 states that "no person shall attach any object to any city property or locate any object on city property in such a manner as to damage the city property, obstruct public right of way or interfere with the function of the city property."

City staff officials have said they're mostly worried about the safety of someone passing by a slackline. What if you forget your line and some Boulder ultramarathoner runs smack into it?

Those ordinances also prohibit hammocks or rope swings, which are handy for jumping across the Boulder Creek (don't say we didn't warn you).

Good news though, if you live on private property or have access to some private trees: you can slackline as much as you want.

Sarah Kuta and Isa Jones contributed to this report.