On Tuesday, lightning struck near a group of eight hikers standing shoreside at popular Mills Lake, about three miles up from Glacier Gorge Trailhead in Rocky Mountain National Park. The strike occurred just after noon. Most of the group, a family of seven and a friend, received ground shocks, but three people - two men and a woman, all from Houston, Texas - were knocked to the ground and received burns. The men were burned on their feet, the woman on her arm. The park received a cell phone call notifying them of the accident at 12:20 p.m., but all victims were were well enough to hike out to trailhead, where they were treated by a waiting ambulance and released.
Surprisingly, lightning does not not rate particularly high as a cause of backcountry deaths, given how common WWIII-level thunderstorms are in desert and mountain terrain - and the fact that most active climbers and peak baggers have been scared witless by it at one time or another. According to the National Weather Service, lightning killed 45 people nationwide in 2007. Most fatalities occurred in Florida (11), Texas (6), and Georgia (3). All other states had two or less. Half (22) of those deaths occurred in June and July. However, only three of these deaths could be termed 'backcountry.' They occurred in Baxter State Park, ME; near Colorado Springs, CO; and in Utah's Uinta Mountains. All victims were camping at the time. In Colorado specifically, lightning injures an average of 15 people each year, and kills an average of three.
Most injuries and fatalities are not due to direct strikes, but come from ground shocks or bolts that jump sideways from trees. It is not uncommon for people to receive silver-dollar-sized burns where lightning enters and exits their body. Burn patterns can also form a web-like grid on the skin.
Virtually all fatalities are due to cardiac arrest; the voltage simply stops the heart, although sometimes that halt is temporary. Like all unconscious injury victims, lightning strikees should be immediately checked for open airway, breathing, and pulse (think "A,B,C-ardiac"). Administer CPR if necessary. It is not uncommon for survivors to suffer temporary or permanent neural damage, but many people walk away from serious nukings.
I once met a Swedish climber, Hans Steyskal, who showed me at least 8 large burns on his back, and a matching series on the soles of his feet. He'd received all of them in the course of an hour, while cowering in a metal bivouac box on the Eiger's Mittilleggi Ridge. Enroute to the ER after that frying, he'd stopped at a cafe for lunch.
Prevention-wise, your best safety measure is a healthy fear of lightning. Avoid it by avoiding thunderstorm weather, and exposed terrain. Keep an eye out for quick cloud build-up, and retreat to low elevations before the thunder starts rumbling. Start summit climbs early and descend before clouds build. Stay off lakes and oceans when bolts are flying.
If you're caught in a serious lightning storm, find a low spot in the ground, away from granitic rocks and large trees (both can conduct electricity). Avoid rock overhangs and small caves, since lightning can arc between ceiling and floor. Get away from water, especially salt water and its conductive ions, and any metal objects like trek poles, climbing hardware, pocket knives and even spare change; They don't actually attract lightning, but can channel currents to fatal effect if a bolt lands nearby. Crouch atop a foam pad if possible, staying on your feet in a "fetal hug" position. And try not to soil your diapers. >:0
I'll admit it: I'm way scared of lightning. My three big brushes with it remain the most terrified I've ever been in 40 years of outdoor travel, and that's including whitewater swims and grizzly showdowns. I've had static electricity sting me like a bee swarm in the Bugaboos. I've literally run screaming down off ridgelines in the Canadian Rockies. And I've cowered under a tarp tent in Colorado's San Juans while an artillery barrage pounded the nearby timber and piled marble-sized hail six inches deep
Certain mountain ranges are notorious for electrical storms. The Sierra Nevada, San Juans, Wind Rivers and the Froze-to-Death Plateau of Montana's Beartooths come to mind. And then there's the Uintas of Utah, where I'm headed tomorrow for a weeklong trek on the Highline Trail. Most of that trip is above 10,000 feet - and timberline. But if the bolts are flying, I'll be happily camping down in the mosquito-ridden swamps rather than up where Odin throws his tantrums.
While the statistics may be modest, I consider lightning to be one of the biggest, and most commonly encountered, threats to my recreational survival. Don't mess with it. --Steve Howe