Bedrock geology of the Yosemite Valley Area Bedrock geology of the Yosemite Valley Area Bedrock geology of the Yosemite Valley Area Bedrock geology of the Yosemite Valley Area http://geomaps.wr.usgs.gov/parks/yos/I_1639.html Bedrock geology of the Yosemite Valley Area Bedrock Geology of Yosemite National Park http://geomaps.wr.usgs.gov/parks/yos/I_1639.html