Yosemite National Park officials announced Monday that nearly 16,000 tons of rock collapsed onto a hiking trail near the Hetch Hetchy Reservoir late last week.
The Fresno Bee reports that the boulders fell from a 500-foot-high cliff east of Wapama Falls and destroyed some 400 feet of the Rancheria Falls trail on March 31. No one was injured in the slide.
Yosemite has one of the highest rockfall incidence rates in the country, with dozens of slides occurring inside the park each year. The majority of these occur in remote backcountry areas and are rarely witnessed firsthand.
Rockfall is most prevalent in spring when ice that had been filling (and expanding) the cracks within boulder formations melts, thus weakening the strength of the outcropping.