Rome plows were large, armored, specially modified bulldozers used in South Vietnam by the United States military during the Vietnam War. First used in III Corps (Military Region III), major land clearing operations commenced in May 1967 upon the arrival of the 169th Engineer Battalion. Prior to plowing operations, preparatory machinegun, mortar, and 90mm tank guns were fired into the forests and jungles, thus clearing a path for the Rome plows to commence their runs, clearing jungle vegetation and cover that could be used by the Viet Cong and North Vietnamese forces. During the American invasion (incursion) into Cambodia on 1 May 1970, Rome plows cleared over acres ( km2) of jungle near the Fishook region, and destroyed over 1,100 enemy positions.