The iconic symbol of Yosemite grandeur, Half Dome just begs to be climbed. The seven-mile route to this granite landmark via the Mist Trail sees 2,500 to 3,000 people per day during summer weekends, making it the most heavily trafficked corridor in the park. People endure fatigue, altitude sickness, and dehydration in their determination to stand atop Half Dome's broad 8,836-foot-high crown. Steel cables bolted into the granite assist climbers up the final 400 vertical feet, but the combination of high, open rock and metal fixtures makes this a lousy place to get caught in an electrical storm. And once the raindrops start falling, the rock becomes treacherously slick. Yosemite's search and rescue team responds to 300 incidents each year–more than any other national park–and not surprisingly, Half Dome claims its share: six deaths since 1995.