 The NVA immediately attempted to remove the Marines from their defensive position, but several attempts at scaling the Rockpile and striking the top and sides with mortar rounds proved ineffective.Operation Prairie swung the momentum for the mountain's fight after waves of Marines stormed into the area to reinforce the troops around the Rockpile and fortify its defenses.From then on the Rockpile was often manned by at least a squad of United States Marines, who received supply drops by helicopters and would go on to launch numerous operations from the base of the mountain.