paved road on top of o`shaughnessy dam; hetch hetchy reservoir visible on the right; yosemite national park; hetch hetchy valley

alpine america area bay california construction dam drinking energy engineering francisco glacial hetch hetchy industry lake landmark landscape mountains national nature nevada outdoors panorama panoramic park paved people popular reservoir right river road san scenery scenic sierra snowmelt source states structure supply system technology top tourism tourists travel united usa valley view visible walking wall water yosemite