Debbie Burns' 55-year-old knees are quivering as much as the aspen trees that blanket the surrounding San Juan Mountains.
But to Burns, perched at the edge of a two-story-high platform wrapped around an old-growth ponderosa pine, her grandson's happiness trumps an aversion to heights so acute she once had to be shoved off a chair lift.
So after watching 11-year-old Colby Moe swoop down the first of nearly two dozen steel ziplines strung across the Tall Timber Resort in southwestern Colorado, the vacationer from Bakersfield, Calif., takes a deep breath — and her own 72-foot-long leap of faith.
"Oh, my gravy!" Burns yells, accepting a congratulatory hug from Colby after gliding to a graceful stop at the next tree. "Now, can I stay here and keep doing the bunny-hill version?"
Not a chance.
Transcending fear is part of the fun at Tall Timber's Soaring Tree Top Adventures. Opened four years ago and tagged by TripAdvisor.com as the USA's most popular attraction based on reader rankings, it's a leading example of a high-wire act that's taking off like Tarzan.
The adventure of strapping into a harness, clipping to a cable, then zipping across a canyon, down a mountain or through a canopy of trees — hence the terms ziplining and canopy tours — was popularized in Costa Rica a decade ago. Now, the elevated excursions are cropping up across the USA, with at least two dozen in operation and dozens more in the works.
Some, like an Alaska zipline that whisks cruise ship passengers more than 1 mile in 90 seconds, are aimed at adrenaline junkies. Others cater to families wanting to both scream and savor the scenery.
Many canopy tours let participants "connect with nature and each other in an otherwise inaccessible environment," says John Walker of Bonsai Design, a Grand Junction, Colo.-based company that has designed seven U.S. zipline courses over the past three years.
That mission certainly applies to Soaring Tree Top Adventures.
Tall Timber owners Denny Beggrow and his son Johnroy created the 5½-hour aerial tour as a way to broaden their remote, 180-acre retreat's appeal. Inspired by Johnroy's childhood treehouses and Sean Connery's rain-forest adventures in the 1992 film Medicine Man, their tour rapidly eclipsed such offerings as fly-fishing and horseback riding among wealthy patrons that have included CEOs, movie stars and vice presidents.
As of this summer, the Beggrows' 10-room resort — accessible only by helicopter or the Durango & Silverton Railroad — no longer accepts new overnight guests. But as many as 60 people a day pay $329 a piece to clamber aboard the steam-powered train in Durango, spend two hours gaping at vistas captured in Butch Cassidy and the Sundance Kid, and get off at Tall Timber to enter a world worthy of Peter Pan and Frodo Baggins.
The unregulated canopy tour industry suffered a high-profile black eye this spring when an American vacationer plummeted to her death from a zipline on the Caribbean island of Roatan, Honduras.
At Tall Timber, would-be soarers must sign an alarmingly detailed liability waiver that flags the activity's uninsured status and notes such possibilities as slamming into or missing a platform, falling from 100 feet and becoming "sick from the swinging motion."
But Soaring Tree Top Adventures' personable "sky rangers," all of whom have 40 hours of wilderness first-aid training as well as climbing and rappelling skills, emphasize the safety of both people and trees.