cook nine prisoners, and captured 14 weapons at a cost of six Marines killed in action, three dead of wounds, and 60 wounded, Boobytraps caused many of the Marine casualties. In August, the battalions reported finding 50 of these devices and accidentally detonating 26.45
The 5th Marines conducted two named operations during the summer. The first. Operation Barren Green, centered on the VC-controlled My Hiep area just south of the Song Vu Gia in northern Arizona Territory. Here large fields of corn had ripened which allied intelligence expected to be harvested by enemy sympathizers and then carried by infiltrators south-westward into the mountain base camps of the 38th NVA Regiment. In an effort to keep the enemy from obtaining this corn, on 15-16 July, a reinforced platoon from the 3d Battalion, in cooperation with RFs from Dai Loc District, protected civilians brought in from north of the river to harvest the crop. In two days, the civilians collected 30 tons of corn, but on the second day enemy sniper fire and boobytraps killed three PFs, wounded eight RFs, five civilians, and 12 Marines, and so frightened the harvesters that the operation had to be discontinued with much corn still standing in the fields.
In Operation Barren Green, from 24 to 27 July, companies from the 2d and 3d Battalions, supported by a platoon from Company C, 1st Tank Battalion, returned to the My Hiep area. In the first phase of the operation, controlled by the 2d Battalion, a cordon and sweep routed our and captured a few enemy. A reconnaissance team nearby ambushed a party of NVA from the 38th Regiment fleeing the area with a load of corn and killed seven of them. In the second phase of the operation, the 3d Battalion took charge and oversaw the destruction of the rest of the standing corn, much of which was crushed by the tanks. When the operation ended on 27 July, the Marines had killed 18 NVA and VC, captured three prisoners and four weapons, and destroyed about 10, 000 pounds of the enemy's corn.46
The 5th Marines' second named operation. Lyon Valley, was also aimed at stopping the movement of food from the northern Arizona 10 the base areas of the 38th Regiment, in this case by blocking trails and destroying camps and caches in the mountains bordering the Arizona area on the southwest. On 16 August, Companies F and H of the 2d Battalion with a battalion command group were inserted by helicopter into mountain landing zones- At the same rime, Company L of the 3d Battalion, under operational control of the 2d Battalion, screened the northern face of the mountains. The 2d Battalion companies pushed northeastward from their landing zones along the Trails toward the blocking company while searching for enemy troops and installations. In two small firelights, Marines of Company F killed three North Vietnamese, but the companies encountered no large enemy units. The trails the Marines followed showed signs of frequent use, and the companies found numerous bunkers, holes, and rocket launching sites. They also came upon several antiaircraft gun positions and in one they captured a 12.7mm machine gun. On 22 August, Companies F and H reached the northern foot of the mountains, where they boarded helicopters and flew back to An Hoa. Company L on the same day returned to the control of the 3d Battalion.
On 23 August;, Companies F and H resumed the operation. With minimal air or artillery preparation of their landing zones, they landed by helicopter in the southwestern Arizona in an effort to surprise and [rap enemy combat and transportation troops who might have hidden there while the earlier maneuvers blocked movement into the hills, The Marines captured only one North Vietnamese soldier, but they found a large quantity of food. Operation Lyon Valley ended on 24 August; results were modest. The Marines suffered no combat casualties, although 11 men were incapacitated by heat stroke and accidents. They killed five enemy and captured one, uncovered and destroyed 13 base camps, and collected two weapons. assorted other ordnance, and over three tons of food.47
Combat Declines, But the Threat Continues
For the Marines-whether combing Base Area 112 in Operation Pickens Barest or patrolling and ambushing in the Rocket Belt, the Arizona Territory, the Thuong Due corridor, and the Que Son Valley-it had been a summer of diminishing contact with the enemy. Throughout the summer, and in fact throughout the first eight months of 1970, Front 4 had withheld most of its main force units from battle. By early September, there were indications thai Front 4's main force strength actually had decreased. Documents captured in Operations Pickens Forest, Lyon Valley, and Dubois Square, supported by other information developed through continuous patrolling by infantry and reconnaissance units, pointed to a consolidation and reduction of Front 4's military command organization and to the disbanding or departure from the province of three of the four North Vietnamese infantry regiments reported there at the beginning of the year.