sional Corps or Prov Corps.* While a subordinate command of III MAF,
Prov Corps included the 1st Air Cavalry Division, 101st Airborne Division,
and 3d Marine Division and was responsible for all operations in northern
I Corps. General Rosson assigned to Major General John J. Tolson, the
commander of the 1st Air Cavalry Division, the responsibility for the
detailed planning of the operation in coordination with the 3d Marine
Division. Rosson also placed under the operational control of the 1st
Air Cavalry Division the 1st Marines, the 11th Engineers, and a Seabee
According to the concept of operations for Pegasus, the 1st Air Cavalry
Division together with the 1st Marines would deploy from positions near
Hue to a new base to be specially constructed at Ca Lu, 16 kilometers
east of Khe Sanh. Capitalizing on its air mobility, the Army division
would advance along the axis of Route 9. Engineers would follow, repairing
culverts and bridges to make the road passable to vehicles. The South
Vietnamese promised an ARVN airborne task force of three battalions
to participate in the operation. D-day was set for 1 April 1968.
Preparations began immediately. The 11th Engineer Battalion and Naval Mobile Construction (Seabee) Battalion 5 joined the 1st Air Cavalry Division engineers in building the base at Ca Lu, to be called "Landing Zone Stud." The project included bunkers, supply storage facilities, and an airstrip capable of handling Fairchild C-123 Provider cargo aircraft. At the same time, the 1st Air Cavalry Division completed the detailed plans for the attack westward and the 3d Marine Division scheduled a deception operation designed to divert the enemy's attention from Khe Sanh to Dong Ha. The 1st Marines at Phu Bai began "extensive retraining and rehabilitation" as a recuperative measure following its participation in the battle for Hue City.110**
The 1st Air Cavalry Division began preparing the battlefield on 26 March when Lieutenant Colonel Richard W. Diller's 1st Squadron, 9th Cavalry began helicopterborne reconnaissance patrols in ever-widening arcs from LZ Stud. Diller's squadron located and targeted NVA positions, and prepared landing zones by directing air strikes using delay-fuzed or "daisy cutter" bombs to blast gaping holes in the dense vegetation.111
At 0600, 30 March, the 3d Marine Division launched the diversionary
operation northeast of Dong Ha. Task Force Kilo, composed of the 2d
Battalion, 4th Marines; the 3d Squadron, 5th Cavalry; and two ARVN infantry
battalions, attacked north toward the DMZ along the coastal plains near
Gio Linh. Encountering light resistance, the task force reached its
objectives the first day, but continued the operation through 1 April
to mask the preparations for Pegasus.112
As a final step for the coming offensive, Operation Scotland at Khe Sanh came to a close on 31 March, and General Rosson at that time placed the 26th Marines under the 1st Air Cavalry for Operation Pegasus.*** Intelligence reports from Khe Sanh indicated that the North Vietnamese were abandoning their positions around the combat base and retiring to Laos, leaving a few units in place to cover the withdrawal. Prisoners reported that NVA units suffered from low morale as a result of heavy casualties and severe supply problems.113 The enemy, reportedly, was having "difficulty coordinating anything larger than a company operation."114 The allied forces poised to attack these battered North Vietnamese units numbered over 30,000 troops organized into 19 infantry battalions with a host of supporting artillery, engineer, and aviation units, making Operation Pegasus "the largest III MAF offensive of the war," up to that time.115
Despite the extensive preparations and high expectations, Operation
Pegasus started not with a bold and powerful thrust, but with a decidedly
more ponderous motion. At H-hour-0700, 1April-foul weather grounded
the helicopters of the 1st Air Cavalry Division, but the men of the
1st Marines, on foot, crossed the line of departure on time, initiating
the offensive. The regiment attacked along Route 9 with the 2d Battalion,
1st Marines north of the road and the 2d Battalion, 3d Marines south
of it. As the infantry moved forward, the 11th Engineer Battalion opened
Route 9, removing mines and obstacles from the road and repairing bridges,
culverts, and bypasses. The 1st Battalion, 1st Marines remained at Ca
Lu, providing security for the recently completed LZ Stud.116
By 1300, the weather cleared, allowing Tolson's 3d Brigade to conduct the planned air assaults into landing zones along Route 9 west of the 1st Marines.
* See Chapter 13 for the establishment of Prov Corps.
** Actually outside of the 1st Marines regimental headquarters, only
the 1st Battalion, 1st Marines had participated in the battle for Hue.
See Chapters 9-12.
*** General Rosson remembered that Major General Tompkins "suggested to me that the 26th Marines be placed under the operational control of the 1st Cavalry Division to facilitate coordination as the relieving forces approached the combat base." Gen William B. Rosson, Comments on draft, dtd 27Feb95 (Vietnam Comment File).