American Slate Co., Walnut Creek, Calif., offers natural slate roofing that provides one of the oldest and most durable roofs available in the United States. The widest range of natural colors and blends allows many choices for any custom roof or commercial project. Large stocks in several warehouses can be shipped nationwide on an immediate basis. American Slate Company works directly with its quarries worldwide (including Vermont slates) giving the customer maximum confidence in materials being purchased.