The glacially carved valley in California known for El Capitan and Half Dome is Yosemite Valley. Located in Yosemite National Park in the Sierra Nevada, it stretches about 7.5 miles and is drained by the Merced River.
The valley’s dramatic shape developed through repeated erosion by streams and glaciers. Granite formed deep underground during the Cretaceous Period, was later exposed by uplift and erosion, and was sculpted by several ice ages. Glaciers carved the steep walls and broad floor, while later sediment from an ancient lake helped flatten parts of the valley.
El Capitan is a nearly 3,000-foot granite monolith on the valley’s northern side and is famous for big-wall climbing. Half Dome, made largely of Half Dome Granodiorite, rises at the valley’s eastern end. A common mix-up is confusing Yosemite Valley with Yosemite National Park: the valley is the park’s best-known geographic feature, but the park encompasses a much larger mountain and wilderness landscape. The Ahwahneechee, a Southern Sierra Miwok group, lived in the valley before American settlement.