EPICENTER: Yosemite National Park, CA
Scenario: You managed to scramble up to that irresistible rock perch where you lorded over the landscape below. But every foothold seems smaller on the descent, and your fingers feel greasy on the wet rock. So you suck your body tight into the cliff, feeling safer but unknowingly increasing your risk: Tilting in rather than standing up straight creates outward force on your feet. You step tentatively onto a tilted stone slab, lower your weight, and your shoes sheer off, freeing your body to experience the full force of gravity.
EPICENTER: Mt. Rainier NATIONAL PARK, WA
Scenario: Four days in, rain starts to fall, filling streambeds and turning trickles into roaring whitewater. The deluge shows no sign of letting up, but you must get back for work, so you brace yourself against the current and step in. Halfway across, your foot sinks into a hole. You topple forward, and your pack pushes you into the swirling maelstrom. Your larynx closes reflexively as water hits your throat. Your lungs will fill after you pass out.
EPICENTER: Mt. Washington, NH
Scenario: You planned to bag the peak in a day–this ultralight stuff is so cool!–so you didn't pack gloves or survival gear. When you first saw the sky darkening, the summit looked close, and you figured it wouldn't take long. But distances above treeline are deceiving–by a factor of two or more–and now the clouds are obscuring your route home. With temps and darkness falling, there's a sickening crack–not lightning, but your tibia, bent too far under the burden of a hasty misstep. Good thing you're wearing clean underwear, because searchers will find your body partially naked: Cold victims typically feel a sensation of overwhelming warmth shortly before expiring.
EPICENTER: Grand Canyon, AZ
Scenario: You packed only a liter of water because you expected to refill at a stream down the trail. But your sunny route is dry as a bone. Thirsty, you hike on, figuring the sooner you find water, the better. But the oppressive heat makes it hard to think clearly. In four hours, your skin clammy and organs cooking, unconsciousness halts your search.