Yosemite Nature Notes 10: Rock Fall
Since the glaciers retreated around 15,000 years ago, rock fall has been the major force of change in Yosemite Valley. Geologists work to understand this force of nature in order to protect the millions of visitors who come here each year.
Did You Know?
In March 1987, the largest historical rockfall in Yosemite National Park deposited an estimated 1.5 million tons of debris at the base of Three Brothers, closing Northside Drive for several months.