From the valley floor, Half Dome looks exactly like its name: a granite sphere sliced cleanly down the middle, its northwest face a sheer vertical wall dropping nearly 2,000 feet. The impression is convincing and completely wrong. Seen from Washburn Point to the south, the formation reveals itself as a thin ridge of rock - an arete oriented northeast to southwest - with its southeastern side nearly as steep as the famous northwest face. Geologists estimate that 80 percent of the supposed missing half may still be there, never having existed as a rounded dome in the first place. What did happen is that a magma chamber cooled slowly thousands of feet underground, crystallizing into quartz monzonite. Erosion and glaciation exposed the solidified chamber and carved it into its present shape. The rock's tendency to fracture along curved surfaces - a process called exfoliation - created the rounded appearance. Half Dome is not half of anything. It is a complete geological object that happens to look, from one specific angle, like something broken.

The steel cables that replaced Anderson's ropes went up in 1919, and they transformed Half Dome from a mountaineering objective into an endurance hike. The route covers 8.2 miles from the valley floor via the Mist Trail, gaining 4,800 feet of elevation along a path that climbs past Vernal Fall and Nevada Fall before reaching the base of the dome itself. The final 400 feet are the crux: a steep pitch up bare rock between two parallel cables mounted on metal poles, where hikers pull themselves upward hand over hand. By the 2000s, traffic had grown to as many as 1,000 people per day, and the Park Service introduced a permit system in 2010 to cap daily numbers at 300. The lottery now receives more than 70,000 applications. Hikers caught on the cables without a permit face fines up to $5,000 or six months in jail. The Cable Route was added to the National Register of Historic Places in 2012 - a recognition that the infrastructure of access had itself become part of the story.

While thousands of hikers pull themselves up the cables each summer, a smaller community approaches Half Dome from the other direction entirely. The northwest face - that sheer wall visible from the valley - hosts over a dozen technical climbing routes that rank among the most famous in North American mountaineering. In 1957, Royal Robbins, Mike Sherrick, and Jerry Gallwas spent five days pioneering the Regular Northwest Face, completing what became the first Grade VI rock climb in the United States. Robbins returned again and again: the Direct Northwest Face in 1963, the Tis-sa-ack route in 1969. In 1967, his wife Liz Robbins became the first woman to complete a Grade IV climb when the couple repeated the Direct route together. The northwest face has since been free-climbed in a matter of hours, a measure of how far climbing standards have advanced since the days when five days on the wall was considered fast.

The Ahwahneechee people did not see a geological formation when they looked at Half Dome. They saw a face. The dark vertical streaks that run down the rock's surface - colonies of brown-black lichens following drainage tracks - looked like tear stains to them. They named the formation Tis-se'-yak, "Face of a Young Woman Stained with Tears," after a figure from their origin stories. John Muir, who climbed the dome shortly after Anderson's first ascent, used the names Tissiack, South Dome, and Half Dome interchangeably in his writings, as if the rock were too large for a single name to contain. In the twentieth century, Half Dome escaped the granite and entered the culture. Ansel Adams photographed it in 1927, creating Monolith, the Face of Half Dome, an image the Sierra Club would use as a symbol of the environmental movement. Adams's ashes were later scattered on the summit. The North Face clothing company adopted a stylized Half Dome as its logo in 1971. The formation appeared on a postage stamp in 1988, on the California State Quarter in 2005, and on California driver's licenses from 2010 until the introduction of REAL ID.

Half Dome's smooth granite becomes dangerously slick in rain, and most accidents on the cable route occur when unexpected storms blow through. At least 25 confirmed deaths have occurred on the cable section since 1919. In July 2024, a sudden rainstorm caught hikers on the descent; a young woman lost her footing and slid beyond her father's reach, tumbling 200 feet to her death. The tragedy renewed calls to double the number of wooden rungs on the cables. The Park Service recommends against climbing when the cables are down for winter or when the rock surface is wet, but the cables remain bolted to the granite year-round, and some climbers attempt the route regardless. The mountain that Josiah Whitney called perfectly inaccessible has become, in the age of permits and lotteries and Instagram, almost too accessible - a place where the line between adventure and tragedy depends on whether the afternoon clouds carry rain.