Craig Cameron Olsen

Craig Cameron Olsen

Get arboreal: Genevieve sets the line, above, skylarking in progress

Genevieve switches on her two-way radio and, like an air-traffic controller, tells ground control who to send up, who's coming down. She needs the radio because at 120 feet it's difficult to understand anyone hollering up from below, especially in this racket the wind is creating. The truth is, there's a lot of hollering anyway. And a whole lot of ropes. There are now seven climbers above, below, and parallel to me. I try, but I can't shake the feeling that somehow we're infesting this tree. To the small crowd of day hikers standing below us, we must look like a pod of caterpillars, dangling by our silks.

In oracular mode Peter Jenkins predicts that, inside of ten years, recreational tree climbing will eclipse both rock climbing and caving in mass participation. He believes this is good news for trees because it will instill what he calls "a heightened tree awareness," which will ultimately lead to more old-growth preservation. Included in the TCI mission statement is a pledge that its members will never harm the trees they climb. Spurs such as those worn by telephone linemen are forbidden, as are various other bark-damaging climbing aids like spikes or hook-ended lag screws. Climbers rely on ropes at all times. And TCI is scrupulous about the use of "cambium savers," nylon tubes, and webbing slings, all designed to protect tender upper bark from rope damage. TCI also encourages climbers to fertilize the trees they climb and to spread gravel at the base of those that receive a lot of foot traffic to protect the root systems and avoid compacting the soil.

In 1970, when I first started rock climbing, I thought it was a sport for renegades and eccentrics, maybe like tree climbing is today. None of us ever dreamed that there would soon be so many people on the rocks that we'd need to switch from high-impact to low-impact gear. Or that, in spite of replacing steel pitons with cams and stoppers, we would eventually degrade many of the best routes simply by overclimbing them. I hope Jenkins is right about the "heightened tree awareness." But I don't believe anyone really knows what effect increased traffic will have on the trees, even if it's traffic from enlightened climbers like the members of TCI. As the sport becomes more popular, of course, some climbers won't bother with the kind of ethical protocol TCI observes and will climb the big ones without much interest in whether it's injurious to the tree or even legal. (Here at Kilmer, we're climbing with the approval of the Forest Service, although Kilmer's rangers may soon impose more stringent regulations. Many public-land administrators, particularly in the West, will not allow their old-growth stands to be climbed at all.)

Then there are do-it-yourselfers like the Midwest man who took a bevy of students up a big maple and left them there, too panicked to get down. Or the kid who rolled out of his hammock high in a Kilmer treetop because he didn't tie himself in securely enough, and sustained a mildly cracked backbone. (The boy was not with TCI; its safety record over 16 years is superb: zero fatalities, zero serious injuries.)

Still, "sometimes you can love a tree to death," worries author Don Blair, a second-generation tree surgeon and the author of the book Arborist Equipment. Blair is skeptical about TCI's ability to both promote the new sport and prevent damage, but mostly he's scornful of that all-too-human tendency for climbers to keep score, a habit that mountaineers disparagingly refer to as "peak-bagging."

Jenkins says that he sees no sign that tree climbers are slipping into a macho "summit or bust" mindset. But records are nonetheless kept of the heights of trees climbed. (Jenkins himself has been up a 357-foot coastal redwood, reportedly the fourth-tallest tree in the country.) And everyone knows that climbing buddies will compete for the fastest ascent, much like motorcycle riders drag racing for beers. When I told a TCIer that I had been up Ariel the day before, she smiled and said, "Yes, but did you go way to the tippy-top?" I was too mortified to admit I had not.