By late 1967, the 12th Marines had become the largest artillery regiment in the history of the Marine Corps. If one included the artillery at Khe Sanh the 12th Marines had some 180 field pieces of mixed caliber ranging from the 105mm Howitzer to the 4.2 inch mortar. COL Edwin S. Schick Jr. the Regimental Commander had under his operational control his four organic Battalions, the 1st Battalions of both the 11th and 13th Marines; the 1st 8-inch Howitzer Battery; the 155mm Gun Battery; two provisional 155mm Howitzer batteries, and the 2d Platoon , 1st Armored Amphibian Company with its six LVTH-6s. In addition, he also had subordinate to him the U.S. Army 108th Field Artillery Group and the Marine 1st Field Artillery Group (1st FAG). The Army group functioned as the administrative and tactical headquarters for the Army 175mm gun and 105mm howitzer batteries attached to the Marine regiment while the 1st FAG performed a similar role for the Marine units. All told, as the year began, the 12th Marines controlled about 35 firing units positioned at 12 different locations spread from Khe Sanh to Phu Bai.