Yosemite Nature Notes: Rockfalls

Despite the towering walls of granite that rim the Yosemite Valley, the place is decidedly not static. Rather, it's a constantly evolving geologic entity that is both deadly and mesmerizing. In this production of Yosemite Nature Notes, videographer Steven M. Bumgardner explains how, since the disappearance of glaciers about 15,000 years ago, rock falls have become the greatest erosional factor in the continued sculpting of Yosemite Valley.