Begin leveling four small patches on the ravine's slope, locating a pair on opposite sides of the gulley where the purchased block piers will rest as foundations for the bridge support beams. These patches delineate the corners of the long narrow bridge where it will span the gulley and must be aligned at true right angles to each other. Use shovels and hand tools to clear debris and dig out soil where necessary to make the areas the same elevation. Throughout the various stages of this project, you should confirm that each subsequent component is both level and "square."
