A yard of river rock weighs 2,700 pounds and is equivalent to 1.35 tons, according to Cedar River Garden Center. A typical skid loader delivers a yard of river rock in two scoops.
The yardage is calculated by multiplying the length by the width in feet times the desired depth in inches. The product is divided by 324 to determine cubic yards. For example, 6 feet times 10 feet times 3 inches equals 60 square feet; 60 divided by 324 equals 0.54 cubic yards, or the equivalent of one scoop from a skid loader. River rock comes in a variety of sizes and colorations and is useful for many projects, such as landscape beds, dog runs, patios, driveways, walks and water features.