One of the most harrowing near-miss stories I've ever heard came from my friend Jason, an itinerant, sometimes-employed climber from Moab. Jason had taken the German girl he was dating to climb Castleton Tower, a 400-foot sliver of sandstone sitting on a ridge above Castle Valley, Utah. The girl was following Jason up the blocks at the base of the tower when a sandstone boulder the size of a Volkswagen shifted beneath her and began to slide. The block rolled over her leg, crushing the bones, and kept going, tumbling off the 50-foot cliff behind them and sliding down into the valley. While the girl narrowly avoided being pulled off the edge, the boulder had shattered her ankle, and she had to return to Germany to have it surgically repaired.
Rockfall like this is frightening because it's one of the only risk factors in climbing that can't be controlled. Falling rock has killed a number of highly-skilled climbers in the past year, including Teva Mountain Games winner Chloé Graftiaux, who fell 2,000 feet last August after a boulder swept her off the side of a mountain near Chamonix. Helmets help, but they're useless against any stone much larger than a baseball.
Last week, rockfall jumped back into climbing news when a group of Canadian climbers released a video of themselves prying a surfboard-sized slab of granite off a route on the Stawamus Chief, a 2,300-foot-high granite dome near Squamish, British Columbia. This practice of tossing loose rock from cliffs, known as "trundling", gained notoriety in 2007 after Pete Absolon, a regional director for the National Outdoor Leadership School, was killed when a hiker threw a bowling ball-sized rock off the top of the cliff he was climbing and onto his head.
Trundling is an especially contentious issue in Squamish. As the number of people developing new routes on the Chief has grown, climbers and hikers have had near-misses with barrages of rocks tossed off the wall by first ascensionists. As Squamish-based climber Kevin McLane wrote in Gripped magazine last year, the trundling has put access to the area in jeopardy as well, with the community just one accident away from blame, liability, and "a near-certain curtailment of climbing opportunities."
"Climbers are risk-takers," Mclane wrote, "and in this case, too often willing to take the chance that for the next five seconds no-one far below is in the way."
The debate took on a whole new dimension last year, when locals discovered that climbers working on a new route had trundled loose rock directly onto Great White North (5.13d), the hardest route up the Chief. The trundlers had inadvertently destroyed fixed hardware on the route, mangling hangers and blowing out bolts. Worse, the falling rock carved "hundreds of white scars" into the lower pitches, potentially altering the character of the route. Without hurting any person, the trundlers had still managed to set back climbing on the Chief.
So why would any responsible climber huck loose stone off of a cliff? For much the same reason that wilderness firefighters light controlled burns: to reduce the danger of a bigger accident happening later. The vast majority of rockfall injuries aren't caused by trundlers, but by rocks cleaned by leaders or loosed gradually by freeze-thaw cycles. The idea is that if the loose rock is removed carefully and deliberately, climbers are less likely to pull a death block down onto their unsuspecting belayer's head. It's worth noting too that the trundlers from this week's video took safety precautions, including closing off the trails below and stationing spotters on the ground to ensure that no hikers or climbers inadvertently wandered into the line of fire.
So trundling has its good side too: an organized group cleaning a popular route is different than a hiker tossing rocks off a cliff for kicks. Still, the benefits are temporary. Erosion eventually makes all rock go rotten, and frost loosens up blocks as fast as climbers can clean them. But for every death flake cleaned-and every trundler who looks before he or she throws-climbers have one less bullet to dodge.