Half Dome - Yosemite National Park, CA. The granite peak of Half Dome rises majestically over Yosemite Valley and Tenaya Canyon. Half Dome was made through the process of exfoliation; where the rock's layers are shed as the result of heat, freezing, or moisture.Half Dome - Yosemite National Park, CA. The granite peak of Half Dome rises more than a kilometer above the valley floor. The rocks that form the dome represent unerupted magma that was later exposed by deep erosion and glaciation. Towering high above the valley, Half Dome is a constant challenge to climbers, providing unparalleled views of Yosemite Valley and the high country from its summit. Film Size 6X7cm