Do I need to Worry About Cliffs, Rockfall and Lightning in Yosemite?

Exploring Yosemite's great outdoors can be fun for all ages, as long as you take simple precautions. Make time before your trip to learn a little about the park's safety hazards, so that your vacation will be carefree.
By Staff,

Exploring Yosemite's great outdoors can be fun for all ages, as long as you take simple precautions. Make time before your trip to learn a little about the park's safety hazards, so that your vacation will be carefree.

Climbing Cliffs & Granite Domes

Yosemite's granite domes and cliffs are part of what makes the park's landscape so inspiring. But those same features also pose the biggest dangers to park visitors. Falling is the number-one cause of injuries and deaths in Yosemite. Many such accidents can be avoided by always standing back from viewpoints (e.g., don't climb out on the tempting rocks of Glacier Point) and not straying off marked trails, especially around cliffs. When hiking up Half Dome, consider starting your hike around dawn, so that you arrive at the base of the summit climb early in the morning when the cables are less crowded. If you're going to be doing any bouldering or rock climbing in the park, consider taking a class or hiring a guide from the Yosemite Mountaineering School, which offers lessons and climbing workshops for all skill levels, from novices to experts.

Lightning

Lightning is another hazard in Yosemite, particularly when hiking and rock or mountain climbing. Check the weather forecast at any visitor center or information station before heading out. Don't attempt to summit any peaks or granite domes during a rainstorm. If you hear thunder within 30 seconds of a lightning flash, get off of exposed ridges and high points, as well as away from water (i.e., out of streams) immediately. Do not keep any metal on your person and avoid standing under isolated tall trees or other potential lightning rods. Injuries can occur after lightning strikes, due to electricity being conducted through the ground. Spread out your group. Encourage everyone to assume a crouched position on the balls of their feet, keeping both feet together and their ears covered. If you have a camping pad, put it under your feet for insulation.

Rockfall

Although rare, rockfall is another hazard in the park. Every year a few rockfalls occur (usually without warning) in Yosemite Valley. These rockfalls are typically minor, but some injuries and deaths have occurred. Of course, park rangers are doing all they can to identify potential rockfall areas, so heed all posted warning signs. Stay aware of your surroundings, especially when walking below cliffs or near the bottom of waterfalls.