granite- sierra water washed boulders Sierra Water Washed Boulders are from the rivers of the Northern California Sierras. Colors are white with gray specs and have some rusty splashes. They are used for landscaping as feature boulders and sitting rocks. They are available in sizes 300–6,000 lbs. AVAILABLE SIZES DESCRIPTION THICKNESS   Landscape Boulders 300 to 6,000 lbs