Yosemite’s Lyell Glacier appears to be receding

“It appears to have stagnated, and we strongly suspect that it has thinned to less than half the size that would keep it moving,” Yosemite geologist Greg Stock tells the Chronicle’s David Perlman. Lyell Glacier stands atop the headwaters of the Tuolumne River, which feeds San Francisco’s Hetch Hetchy reservoir. It’s the largest of 14 glaciers in the High Sierra that has shrunk by more than half in the last century.

Image: Fred Sharples via Flickr