Alternatively, over a dozen rock climbing routes lead from the valley up Half Dome's vertical northwest face. Other routes ascend the south face and the west shoulder. The first modern technical route was the Regular Northwest Face route - originally climbed in 1957 by Royal Robbins, Mike Sherrick, and Jerry Gallwas. This 5-day ascent was the first Grade VI climb in the United States.
Half Dome is nearly as whole as it ever was. The impression from the valley floor that this is a round dome which has lost its northwest half is an illusion. From Glacier Point or from Washburn Point, Half Dome can be seen as a thin ridge of rock oriented northeast-southwest, with its southeast side almost as steep as its northwest side except for the very top. Although the trend of this ridge, as well as that of Tenaya Canyon, is probably controlled by master joints, 80 percent of the northwest "half" of the original dome may well still be there. What probably happened is that frost splitting of the rock at the back of a tiny glacier against Half Dome above Mirror Lake gradually quarried back the steep northwest face. As the base of the cliff was hewn away, ultimately parts of the sheets parallel to the original upper surface of Half Dome were left projecting outward at the crest of the vertical cliff.
Half Dome was originally called "Tis-sa-ack," meaning Cleft Rock in the language of the local Native Americans. Tis-sa-ack is also the name of the fourth route on the formation, ascended by Royal Robbins and Don Peterson over eight days in October 1969. Tis-sa-ack is the name of a mother from a native legend. The face seen in Half Dome is supposed to be hers. Tis-sa-ack is the name of a Mono Lake Paiute Indian girl in the Yosemite Native American legend.
Half Dome is the inspiration behind The North Face corporate logo.
The Half Dome Cables Route hike runs from the valley floor to the top of the dome in (via the Mist Trail), with of elevation gain. The length and difficulty of the trail used to keep it less crowded than other park trails, but on long summer days there can still be a large crowd at the top and on the trail. The hike can be done from the valley floor in a single long day, but many people break it up by camping overnight in Little Yosemite Valley. The trail climbs past Vernal and Nevada Falls, then continues into Little Yosemite Valley, then north to the base of the northeast ridge of Half Dome itself.
The final ascent is steeply up the rock between two steel cables used as handholds. The cables are fixed with bolts in the rock and raised onto a series of metal poles in late May (the poles do not anchor the cables). The cables are taken down from the poles for the winter in early October, but they are still fixed to the rock surface and can be used. The National Park Service recommends against climbing the route when the cables are down and when the surface of the rock is wet and slippery. The Cable Route is rated class 3, while the same face away from the cables is rated class 5.
The cable route can be crowded. As many as 1,000 hikers per day sometimes climb the dome on a summer weekend. Gloves are recommended for the cable climb, as is proper conditioning, plus sufficient water and food. In past years, a pile of gloves left by hikers could be found by those who did not bring their own , but as of summer 2007 this pile has been removed as litter by park rangers, and a sign suggests hikers not leave gloves. As of summer 2008, the pile of gloves has returned, and no signs advising against leaving gloves are present.
The top of Half Dome is a large, flat area where climbers can relax and enjoy their accomplishment. The summit offers views of the surrounding areas, including Little Yosemite Valley and the Valley Floor. A notable location to one side of Half Dome is the "Diving Board," where Ansel Adams took his photograph, "Monolith, The Face of Half Dome (1926)."
From 1971 through August 2007, there have been nine fatal falls from the cables, three in 2007. On June 16, 2007, Hirofumi Nohara, a native of Japan working in Sunnyvale, California, slipped and plunged to his death..