Yosemite is a granite valley in California walled by a single unbroken cliff nine hundred metres high, and it is a park because of photographs. In 1861 Carleton Watkins hauled a mammoth-plate camera up here and came back with luminous prints of the cliffs and the falls, the first most people in the east had ever seen of it. A senator passed them around Congress, and in 1864 Lincoln signed the valley over to be kept as it was. No government had ever set land aside for preservation, and the phrase national park did not yet exist. The composing has never stopped. Tunnel View, at the mouth of the Wawona Tunnel, arranges the valley for you: El Capitan on the left, Bridalveil Fall on the right, Half Dome closing the far end. The last light leaves the floor first, so the walls stay burning while everything beneath them turns blue.
El Capitan is why climbers come. Its blank face is the most important wall in the sport, and from the meadow below you pick out dots inching up by day and, after dark, headlamps of people sleeping in tents hung off the rock. The first ascent, in 1958, took forty-seven days over eighteen months. In 2017 Alex Honnold climbed it alone, without rope, in under four hours. Yosemite Falls comes off the cliff for 739 metres, the tallest in North America, and in spring the snowmelt soaks the trail beside it. At Mariposa Grove stand the most massive living things on Earth. One low branch of the Grizzly Giant, close to three thousand years old, is thicker than most whole trees. Half Dome is the rite of passage. Its last 120 metres go up the curved back so steeply that the park bolts two steel cables to the granite, and you haul yourself up with your boots skidding. Glacier Point watches the same dome from a thousand metres up. And for two weeks each February the setting sun catches Horsetail Fall head on, and the thin ribbon burns orange for a few minutes in front of a meadow packed with cameras.