Boulders, Yosemite National Park

Photograph by Fritz Hoffmann , National Geographic

Boulders perch randomly at Olmsted Point in Yosemite National Park . A glacier sculpted the 92-million-year-old bedrock here and left the boulders, plucked from a nearby mountain, when it retreated. The rocks, along with grooves in the bedrock, show the path of the glacier.