Rising nearly 5,000 feet above Yosemite Valley and 8,800 feet above sea level, Half Dome is a Yosemite icon and a great challenge to many hikers. Despite an 1865 report declaring that it was "perfectly inaccessible, being probably the only one of the prominent points about the Yosemite which never has been, and never will be, trodden by human foot," George Anderson reached the summit in 1875, in the process laying the predecessor to today's cable route. https://www.nps.gov/yose/planyourvisit/halfdome.htm
