A popular climbing route at Half Dome in the Yosemite National Park may have been altered after part of the iconic granite monolith's face collapsed last week, officials said Tuesday.
Climbing rangers were assessing changes to the Regular Northwest Face climb after a triangle-shaped slab of rock, roughly 200 feet long and composed of relatively thin granite, tumbled off Half Dome, park geologist Greg Stock said.
While large, rock falls of this magnitude are relatively common at the park, Stock said, and occur about once a year in a process known as exfoliation. Water, ice, earthquakes and plant growth could trigger unpredictable falls.