Mount Lyell, in California, is the highest point in Yosemite National Park at 13,114 feet. At the southeast end of the Cathedral Range near Lyell Canyon and Tuolumne Meadows, it was named, along with nearby Lyell Canyon, for geologist Charles Lyell. The mountain overlooks Lyell Glacier, now regarded as a permanent ice field rather than a living glacier, reflecting a notable environmental change. Mount Lyell also anchors the surrounding landscape by dividing the Tuolumne River watershed, the Merced River drainage, and Rush Creek in the Mono Lake Basin. Its dark volcanic granite and routes over unstable terrain make the ascent challenging despite its popularity.