A shelf system mounts to a wall and has a pair of mounting rails mounted to the wall. The mounting rails are elongated, vertically oriented, and spaced-apart from one another. The mounting rails have an array of bores extending laterally into and arrayed vertically along the mounting rail. A shelf is coupled to and between the pair of mounting rails. Lateral apertures in lateral sides of the shelf receive fasteners extending laterally through the lateral apertures and into the array of bores in the mounting rails. The shelf can be formed of a single piece of sheet material bent to form a horizontal platform, lateral sides, and longitudinal tabs.