An articulating composite surface covering mat and process of forming the mat which has multiple units having a regular, natural or irregular appearance, and each unit a flexible geogrid extending therethrough. A method of forming the mat includes forming the mat upside-down on a bottom surface of a bottom mold, placing the top mold over the bottom mold to form the mold assembly, locating a geogrid in the mold assembly, latching the mold assembly together with magnets, and adding the filler to the mold assembly.