Whether the sacrifice of Siberia in favor of the seizure of Bunker justified the outcome can be determined, in part, by looking back to the division commander’s reasons for this decision. He had cited three advantages in seizing and occupying Hill 122 instead of 58A. One, tactical surprise achieved by an attack on the former, was an unqualified success. That Bunker Hill would provide more defensible terrain and at the same time add strength to the main line were two sound judgments that the test of time would bear out. The third point, that observation into the enemy’s outpost line would be increased from the higher hill, also proved to be correct.

Only the inability to neutralize Hill 58A effectively from Bunker cast any doubt on the considerations. At night the enemy could occupy Siberia both for firing positions and flank security to attack friendly forces moving down the corridor east of Hill 122. Action to counter these two enemy actions came mainly from MLR forces.

One measure of the results of the Bunker Hill fighting is seen in the price paid. Chinese losses were estimated by the 1st Marine Division at approximately 3,200, including more than 400 known dead. Marine casualties in the action were 48 killed and 313 seriously wounded. Several hundred additional wounded were treated at 1st Marines medical facilities and returned to duty shortly thereafter.

To replace combat losses in the infantry regiment, General Selden on 12 August directed that rear area service and support units fill the vacancies. Two hundred Marines, nearly all of them volunteers, were provided to Colonel Layer by the 14th. To offset other losses within the division, its commander similarly had requested on 12 August that the Commandant, General Lemuel C. Shepherd, Jr., authorize an air-lifting of 500 enlisted Marine infantrymen to the 1st Marine Division as soon as possible. Pointing out that mounting battle casualties had reduced the effective strength of the division, General Selden also urged that each of the next two monthly replacement drafts scheduled for the division be increased by 500 more enlisted men. After some debate at the next senior administrative headquarters,197 the request was granted by General Shepherd, and the emergency replacements were made available from the 3d Marine Division at Camp Pendleton, California. The initial replacement of 500 Marines arrived on 21 August.

More men to replace divisional combat losses might have been required had not the medical support been such an efficient operation. After the battle, the regimental surgeon, Lieutenant Robert E. Murto, called for a review of the medical facilities in effect during the Bunker, Siberia, and Stromboli fighting. In attendance were the battalion doctors and the division surgeon, Captain Lawrence E. Bach. Participants discussed both the major difficulties and routine procedures involved in medical care of the wounded. Problem areas were the high incidence of heat exhaustion, ground transportation of the wounded, enemy artillery fire that interfered with helicopter evacuations, and the need for increased medical support under battle conditions.

Regarding the last category, the surgeons noted that medical supplies during the heavy fighting of 9–16 August were never at a dangerously low level. The only shortage that had developed was in stretchers, due to the normal delay in transfer of stretchers from medical stations along the evacuation route to the company forward medical facilities. To help combat the Chinese artillery problem, medical officers had placed aid stations on the reverse slopes of hills. There was no available or known solution to hastening and easing the movement of battlefield casualties over the ground. The armored personnel carrier offered some protection from ground fire and a ride less painful than one in a truck, but the wheeled vehicles remained the most widely used.

There was little that could be done about the number of heat exhaustion cases. High temperature and humidity, vigorous activity, and the wearing of the armored vest (and to some degree, the steel helmet), combined to produce the casualties. All the surgeons agreed that regardless of the number of heat casualties, the wearing of these two items must continue. Regimental doctors credited the armored vest with saving the lives of 17 Marines. Several other Marines, they noted, had received only slight head wounds from bullets that had spent most of their velocity penetrating the steel helmet.

Helicopter evacuation saved the lives of other Marines. The doctors credited the flying skills and bravery of the evacuation pilots for these rescues. Immediate response to day and night calls was instrumental in the recovery of numerous Marines. Rear Admiral Lamont Pugh, Surgeon General of the U.S. Navy, commented upon the value of the helicopter and on other reasons for success of medical support. After a Far East inspection trip, which included a visit to the 1st Marine Division during the battle of Bunker Hill, Admiral Pugh expressed the following opinion:

In another logistical area, the performance was not quite as satisfactory, for the level of supply of one important item—illuminating shells—fell dangerously low during the Bunker fighting. On 16 August, 3/1 reported early in the morning that “artillery illumination was exhausted and 81mm mortar illumination was fast diminishing.”199 To replace the shell-produced light, the regiment used a flare plane.200

Ammunition supply appeared to be no problem to the Chinese. The rate and frequency of mortar and artillery fire proved that the enemy had a vast store of these shells. During the heavy fighting, the division observed that the enemy expended approximately 17,000 mortar and artillery rounds in the 11–16 August period of the battle. It was noted for the first time that the Chinese used mortars primarily in support of limited attacks.

About the enemy’s reliance on mortars and the technique of their employment, the 1st Marine Division reported:

Further information about the Chinese was also derived at this time, although not always directly associated with the battle. Deserters picked up in the left sectors of the 1st and 5th Marines on 12 and 13 August and papers taken from enemy dead on the 13th confirmed earlier-reported dispositions of Chinese units. One prisoner, from the artillery regiment of the 118th Division, the unit facing the major part of the 1st Marines line, indicated that another artillery regiment had been assigned to support his division. If true, this extra unit would account for both the increased Chinese fires in the Bunker area and the additional artillery emplacements that photo planes had spotted in the 118th Division sector. Infantry units of this division, the Marines observed, introduced no new techniques or equipment during the battle. Prior intelligence had provided the 1st Marines with typical enemy ground attack tactics. Neither the Chinese envelopment of Siberia, Stromboli, and Bunker nor the diversion against Hill 48A before the main attack on Hill 122 represented a departure from normal CCF practice.

Nor was the earlier Marine diversion new, but unlike the Chinese attempt, the 1st Marines tactic was successful. Just before the maneuver, the division pulled off another strategem, described by General Selden in a letter to General Shepherd:

One technique the Marines employed in the Bunker Hill battle was defense of the reverse (protected) side of the hill. Although counter to the usual American military practice, the reverse slope defense was required by the intense artillery and mortar fire massed upon the front slope defenders. As the 3/1 battalion commander later commented:

On the other hand, a tactical weakness of the reverse slope defense, that “plagued us until the end of the battle,”204 was the fact that the 1st Marines initial gain was not more fully exploited. As the battalion commander explained:

Some officers felt, in retrospect, that a more feasible solution during the August battle might have been to move all three battalions on line—3/1, 1/1, and 2/1, with the reserve battalion (1/1) deployed on a narrow front. This would have provided decisive strength on Bunker and the MLR behind it to give greater depth counterattack capability, and better control at the point where needed.206 Departure from standard doctrine by employment of the reverse slope defense furthered the existing controversy as to the best method of ground organization in the division sector. But it was to be some months before a change would be effected.207

Tank, artillery, air, and ground Marines participating in the battle of Bunker Hill gave up one outpost but took another, one that added strength not only to the outpost defense but also to the main line. A well thought-out plan and its skillful execution permitted Marines to take the critical terrain quickly without crippling casualties. Defense of the position on Hill 122 was complicated not so much by the Chinese infantry action but by the intensive mortar and artillery shelling. The Marines’ capability to defend was enhanced by close coordination among artillery, air, and tank units. Chinese casualties, by estimate, were 500 percent more than the losses actually suffered by the Marines. The battle of Bunker Hill resulted in the first major Marine action and victory in West Korea. It ushered in two straight months of hard fighting, the most difficult ones yet for Marines on the western front.