El Capitan, a sheer granite monolith rising about 3,000 feet above Yosemite Valley, is one of the United States’ best-known rock formations and a defining landmark of big wall climbing. Named in 1851 by the Mariposa Battalion, its name has been linked to the Native name Tutokanula, whose meaning has been interpreted in different ways. Geologically, the cliff is mostly 100-million-year-old granite shaped by glaciation and preserved by its relative resistance to erosion. In climbing history, routes such as The Nose, Salathé Wall, and Muir Wall became milestones in aid, free, solo, and free solo climbing, making El Capitan a lasting touchstone of the sport.