Yosemite Granite Boulders Central California River Rock Granite Yosemite granite boulders are characterized are ancient river boulders are commonly a rusty orange, or tan-gold or brown color, sometimes available in grey color tones. The sizes of these boulders commonly range from 12" to 36" in size, but larger specimen sizes are available. Yosemite granite boulders with their smooth creating a warm and earthy aesthetic in the landscape. As a type of granite, they possess the durability and strength that make them suitable for various landscaping purposes. The texture of these boulders is typically smooth, showcasing the natural beauty of the stone but also making these much safer for parks, playgrounds and other areas children and people gather.