I Corps Operation Orders No. 31 and 32 had directed that the 11th Marines remain on line in the sector attached to I Corps Artillery, with a general support mission of reinforcing the fires of the 25th Division artillery, and a secondary task of coordinating counterbattery support. The medium battalion, 4/11, and the 1st 4.5-inch Rocket Battery, furnished general support for I Corps. Regimental and battalion CPs, as well as the rocket battery, continued to occupy their same locations. A change affected the KMC artillery battalion, however; when transferred to I Corps artillery control it displaced from the Marine sector, with a new general support role of reinforcing the I Corps line.

Also on 5 May, at 1130, the 1st Tank Battalion416 passed to 25th Division control. Two companies, C and B, were assigned to the TAFC (which had no armored units) in the left and right battalion areas, respectively. Company D vehicles came under command of the 35th Infantry Regiment, in the center sector; while A, the remaining company, was designated as the single reserve unit. This was a modification of the Marine system of maintaining two tank companies in reserve, one a short distance behind the MLR and the other, at the armored battalion CP near Munsan-ni. A change in tactics also took place when the Marine tanks came under Army operational control. It had been the Marine practice to retain the tanks at the company CP from where they moved to prepared firing slots at the request of the supported infantry unit.

When the 1st Tank Battalion was attached to the 25th Division, the armored vehicles were shifted to firing slots near the MLR where they occupied semifixed positions.417 Armored personnel carriers (APCs) were assigned by the Army to Company B and used by both B and C as resupply vehicles to haul food, water, fuel, and ammunition to the tanks on line. Also as part of the relief, control of the KMC tank company was transferred from the Marine 1st Tank Battalion to I Corps, although the company still continued in its same location in the old KMC sector.

Also remaining in their same positions were MASRT-1 (Marine Air Support Radar Team One), in support of the 25th Infantry Division, MTACS-2 (Marine Tactical Air Control Squadron Two), and VMO-6. The mobile air support section of the observation squadron, however, had moved with the 1st Marine Division to the new Casey area for participation in the coming MARLEX operations scheduled during the reserve training period.

Thus with the relief completed, components of the old Marine division front, from left to right, were: the Kimpo Provisional Regiment; Task Force Track; the 27th Infantry Regiment; 35th Infantry Regiment in the center sector, including its armor and heavy mortar company and 2d and 3d Battalions forward, replacing the 1st Marines 3d and 1st Battalions; and in the right sector, the Turkish Brigade 4.2-inch mortar company and its 1st and 3d Battalions initially located418 in the MLR positions vacated by the 2d and 3d Battalions, 7th Marines.

In addition to the 1st Marine Division railhead and truckhead at Munsan-ni and Ascom City, a subsidiary railhead/truckhead was opened at Tongduchon-ni, two miles southwest of the new division CP at Casey. No change was made in the airhead at K-16. Effective with the 5 May change, remaining elements of the division CP staff at Yongji-ri joined the advance elements at Casey. As the Marines moved off the front lines they received “well-done” messages from the Commandant, General Shepherd, and the U.S. Pacific Fleet Commander in Chief, Admiral Arthur W. Radford, as well as the new I Corps Commander, Lieutenant General Bruce C. Clarke419 who cited the “excellence of the planning, coordination and cooperation which enabled the operation of the past few days to be successfully accomplished.”420

Training While in Reserve and Division Change of Command421

While the division was in reserve, its tactical mission consisted of preparation for commitment on I Corps order as a counterattack force in any of the four division sectors of I Corps. Division Operation Plan 7-53 implemented this I Corps Plan “RESTORE” and set forth the designated blocking positions in the 25th Army, Commonwealth, 1st ROK, and 7th Army Division sectors in event of threatened or actual enemy penetration of the MLR.

The 1st Marine Division’s Training Order 8-53, issued on 6 May, the day after the relief was officially effected, outlined the training to be accomplished during the eight-week reserve period, 10 May-5 July. Following a few days’ interval devoted to camp construction and improvement of facilities, an active training program commenced. Its objective was the continued improvement of amphibious and ground offensive combat potential of all personnel. Three major regimental combat team MARLEXES were scheduled.422 The training syllabus called for a four-phased progressive schooling from individual to battalion and regimental level conducted in all phases of offensive, defensive, and amphibious warfare. Weaponry familiarization, small unit tactics, and combined unit training, with tank-infantry deployment and integration of helicopters at company-level exercises, were emphasized, culminating in a week-long field maneuver.

Lectures were to be kept to a minimum, with at least 50 percent of the tactical training conducted at night. Specialty training in intelligence, signal communications, antitank and mortar, machine gun, mine warfare, and staff NCO schools was also prescribed. Numerous command post exercises were programmed to obtain a high standard of efficiency in both battalion and regimental-level staff functioning. It was the first time the division had been in reserve since a brief two-week period in late July-August of 1951. A brisk 40–44 hour week, plus organized athletics, insured that the training period was to be fully utilized.

No time was lost getting under way. At a staff conference with battalion commanders on 11 May, General Pollock, division CG, stressed the importance of using the time they were in reserve for enhancing division combat-readiness. Even as he spoke, his 5th Marines had the day before boarded ships at Inchon and were en route to the Yongjong-ni landing area for MARLEX I. Since the 5th Marines, in division reserve, had been the first of the regiments to displace and on 1 May had turned its sector over to the incoming 14th Infantry Regiment, it got the jump on training during the reserve period. Regimental Operation Plan 12-53, of 28 April, had outlined requirements for the 5th Marines RCT LEX 1; from 2–9 May the regiment had participated in a week of intensive amphibious training, including reduced and normal distance CPX dry runs for the coming MARLEX.

With ships from CTE 90.85,423 and air defense by VMFs-311 and -115, Colonel Tschirgi’s RCT-5 made the D-Day landing on 13 May with its two assault BLTs securing the objective. An unexpectedly shallow beach gradient and difficulties encountered in unloading vehicles from the causeway resulted in less than a 100 percent performance rating. These were deficiencies that might have been prevented had not the customary rehearsal been cancelled the previous day when a heavy fog obscured the landing beaches. Besides regimental antitank and 4.2-inch mortar units, participating support elements included Company D, 1st Tank Battalion; Company A, 1st Armored Amphibian Battalion; Company C, 1st Engineer Battalion; 1/11; and helicopters from HMR-161 and VMO-6.

Meanwhile, on 15 May, command post and subordinate units from the 1st, 5th (less RCT-5 currently deployed in MARLEX I), and 7th Marines and support elements took part in a one-day division CPX at Camp Casey stressing mobility, security and operational procedures. Another CPX on 22–23 May by 11th Marines and engineer personnel emphasized dispersion, camouflage, and message handling under simulated combat conditions. Units of the three infantry regiments plus the KMCs training with the 7th Marines at Indianhead combined in a CPX-FEX (command post-firing exercise) on 26–27 May. Realism bowed to current ordnance supply economics in that ammunition was carried for individual weapons, but it would “not be loaded except on specific orders from an officer.”424

The CPX-FEX was held as a trial exercise for an Eighth Army CPX scheduled later in the month, which was postponed indefinitely on 29 May because of the critical battlefront situation and continuing enemy attacks across the EUSAK front. Extensive preparations were also underway for MARLEX II, with RCT-7, from 2–10 June; and concluding MARLEX III, scheduled 14–23 June, with RCT-1.

Armor and advance regimental elements had left for the Ascom City-Inchon staging area by 1 June, preparatory for departure to the Yongjong-ni beaches on the Korean west coast in the vicinity of Kunsan. The troop list included approximately 250 officers and 4,450 enlisted from Colonel Funk’s 7th Marines and support units, including USN and KMC. Infantry personnel from the regiment’s three battalions formed the three assault teams plus a reserve battalion composed of 475 Korean Marines designated as BLT 5/KMC. Regimental support units included Company C, 1st Engineer Battalion; Company D, 1st Medical Battalion; Company C, 1st Shore Party Battalion; Company B, 1st Armored Amphibian Battalion, and various motor transport, amphibian truck, military police, and helicopter detachments.

R-Day on 5 June went off per schedule. Despite intelligence estimates which cheerily predicted that only “nine days of rain can be expected during the month of June”,425 RCT-7 drew one out of the barrel with its D-Day landing, 6 June. This took place during heavy rains and decreased visibility which threw the boat waves off phase by minutes and required more than the allotted time for HMR-161 troop and cargo lifts.

Use of a 144-foot-long M-2 steel treadway pontoon bridge loaned by the Army, emplaced from the end of the causeway to the beach high water mark, was considered highly successful. It solved unloading problems encountered in the earlier MARLEX, in that all heavy equipment and vehicles were landed on the designated beaches. Further experimentation with this novel employment of the M-2 was recommended to test the coupling system of bridge and causeway during periods of heavy surf. On the minus side, shore party officers noted that night transfer operations had been hindered because of the lack of running lights on the amtracs.

On 9 June, as RCT-7 was on the way back from its amphibious exercise, a directive from ComNavFE (Vice Admiral Robert P. Briscoe) notified the division of cancellation of the forthcoming RCT MARLEX III. All available shipping was being held on 24-hour readiness for the expected final repatriation of POWs (Operation BIG SWITCH). All afloat training exercises by Marine, Army, and Navy units between 6 June and 15 October were to be cancelled.

The division was host to ranking I Corps, Eighth Army, Korean, and 1st Commonwealth officials when a special helicopter assault demonstration was staged 11–12 June at Camp Casey. Two rocket launcher sections, 14 HMR-161 copters, and 2/5 infantrymen were deployed to show the diverse combat capabilities of the aerial workhorse. While in I Corps reserve, the division was also host—and winner—of the I Corps Pistol Matches. And 3/11, which the previous month had taken the Army Training Test 6-2 (a) Modified, was notified the battalion had scored 92.91 percent and received congratulations from the CGs, I Corps Artillery and Eighth Army.

A change of command within the 1st Marine Division took place on 15 June with the arrival of Major General Randolph McC. Pate. The retiring CG, General Pollock, was presented the Distinguished Service Medal by the I Corps commander, General Clarke, for his “outstanding success in the defense of Carson, Vegas, and Elko.” The previous month, General Pollock had received the Korean Order of Military Merit, Taiguk for his active part in the formation, development, and training of the Korean Marine Corps. Attending the change of command ceremonies were General Megee, CG 1st MAW, General Schilt, CG AirFMFPac, and other Marine, I Corps, Commonwealth, and Korean senior officers.

The new 1st Marine Division CG was coming to his Korean post from Camp Lejeune, N. C. where (like General Pollock before him) he had most recently commanded the 2d Marine Division. Commissioned originally in the Marine Corps Reserve in 1921, General Pate was to later rise to four-star rank. Prior to World War II, he had seen expeditionary service in Santo Domingo, in 1923–1924, and in China from 1927–1929, and also served in Hawaii. For his outstanding service and skill in complicated staff duties, first at Guadalcanal, and later during amphibious operations at Peleliu, Iwo Jima, and Okinawa, General Pate had been awarded the Legion of Merit and a Gold Star in lieu of a second Legion of Merit.

After the war, he had served two tours as head of the Division Reserve, in 1946 and 1951. Other assignments included Director of the Marine Corps Educational Center at Quantico and Deputy Director of Logistic Plans in the Office of the Joint Chiefs of Staff.426

Heavy May-June Fighting427

After the early May change of lines, the Chinese lost little time in testing the new UNC defenses. Shortly after 0200 on 15 May, the CCF directed a two-battalion probe on the Carson-Elko-Vegas trio and the Berlin-East Berlin outposts newly held by the Turkish brigade. Supported by heavy concentrations of mortar and artillery, one battalion of enemy soldiers moved against each of the two major defense complexes. Marine Company C tanks, occupying the firing slots that night, accounted for heavy enemy losses in the action, estimated at 200 CCF killed and 100 wounded. Assisting the TAFC Field Artillery Battalion in throwing back the attack were 1/11, 2/11, and 4/11 which sent 3,640 rounds into the sharp four-hour engagement.

The TAFC defense was further reinforced later that day with 21 air strikes against hostile personnel and weapons positions north of the Turkish sector. Adding their weight to the clash, 3/11 and the rocket battery also brought their guns into action, for a combined 5,526 Marine rounds428 dispatched against the enemy.

It was not until 25 May, after the UNC had made its final offer at the truce talks, however, that CCF artillery really began to open up on the Nevada complex. The increased activity by hostile pieces, during the 25–27 May period, was duly noted by the artillery Marines who laconically reported, “Operations followed the recent pattern: enemy shelling of the Turkish Brigade increased during the afternoon; no contacts were reported.”429

This latter situation changed abruptly on 28 May. Beginning at 1800, major elements of the Chinese 120th Division launched simultaneous attacks over 17,500 yards of I Corps front that stretched from COP-2 eastward to that consistent trouble-spot, the Nevada Cities, on to the Berlins, and finally the Hook area in the adjacent Commonwealth Division sector. Supported by heavy artillery fires, one CCF battalion moved in towards Carson and Elko. Another battalion,430 under cover of smoke, attacked central COP Vegas, while a third struck Berlin and East Berlin on the right flank. Three hours after the initial attack, defenders at Carson and Elko were engaged in hand-to-hand combat with the Chinese.

By midnight the men of the 35th Infantry had beaten back the attack at COP-2. The Turks, likewise, were still in possession of the two Berlin (platoon-strength) outposts, but Commonwealth forces were involved in a pitched battle at Ronson and Warsaw. The situation was even grimmer at this time in the Nevada Cities area outposted by the TAFC. Although the Turkish troops continued to hold Vegas, where 140 men were dug in, Carson (two-platoon size) had fallen and Elko (platoon-strength) was heavily besieged. Shortly thereafter, the 25th Division ordered that the TAFC withdraw from the latter position to its own MLR. The diversionary attack against Berlin-East Berlin had been broken off and the twin positions were secured.

During the first six hours of the attack, the night of 28–29 May, Colonel Mills’ 11th Marines, now under I Corps command, had sent 9,500 rounds crashing into Chinese strongpoints, while Marine air observers directed eight missions against active enemy artillery positions. Ripples from the 1st 4.5-inch Rocket Battery, transferred to the Commonwealth sector to support the Hook defense, were fired on CCF troop activity there. Another curtain of flame engulfed the Carson intruders. When the fighting started, 15 Marine tanks were positioned in the Turkish sector. Company B and C vehicles, under Captains James M. Sherwood and Robert J. Post, relentlessly pounded the approaching CCF columns, while Company D was put on a 30-minute standby. As the action developed, additional tanks were committed until 33 were on line at one time or another.431

When savage Chinese pummeling of the 25th Division outposts continued the following day, Colonel Nelson’s 1st Marines was transferred at 1315 to operational control of I Corps. The regiment’s three infantry battalions, antitank, and heavy mortar companies promptly moved out from their Britannia headquarters and within two hours had relocated at 25th Division bivouac areas south of the KANSAS line in readiness for counterattack orders. The 1st Marine Division Reconnaissance Company was similarly ordered to 25th Division control to relieve a 14th Infantry Regiment reserve company in position along the east bank Imjin River defenses.

Overhead, close air support runs were being conducted by pilots of Marine Attack Squadrons 212, 121, and 323. A series of seven 4-plane strikes hit repeatedly from noon on those Chinese troops, hardware, and resupply areas north of the 25th Division line. The aerial assault continued late into the night with MPQ missions executed by VMA-121 and VMF-311.

During the 29th, control of the Vegas outposts—where 1st Division Marines had fought and died exactly two months earlier—changed hands several times between the indomitable Turkish defenders and the persistent Chinese. By dark, the CCF had wrested the northern crest from the TAFC which still held the southeastern face of the position. In the 24-hour period from 1800 on the 28th through the 29th, the 11th Marines had expended 41,523 rounds in 531 missions. At one point in the action Chinese counterbattery fire scored a direct hit on Turkish gun emplacements, knocking six howitzers out of action from the explosions of charges already loaded. As a result 2/11, under its new battalion commander, Major Max Berueffy, Jr., took over the direct support mission of the TAFC Brigade. Marine artillery spotters on station from 0450 to midnight directed 42 fire missions on CCF guns, while the rocket battery unleashed 20 ripples against troop activity, one of which caused 50 WIAs. Although an Allied counterattack early in the day had restored Elko to friendly control, the enemy refused to be dislodged from Carson.

I Corps had previously regarded the defensive positions of the Nevada complex as “critical,” with the TAFC having been “instructed to hold them against all enemy attacks.”432 By midday on the 29th, however, the I Corps commander, General Clarke, and 25th Division CG, General Williams, had apparently had a change of mind. The Vegas strength was down to some 40 Turks. Altogether more than 150 men under the 25th command had been killed and another 245 wounded in defense of Nevada positions. It appeared that the Chinese, constantly reinforcing with fresh battalions despite estimated losses of 3,000, intended to retain the offensive until the outposts were taken.

With Carson and Vegas both occupied by the enemy, the Elko position became untenable without the support of its sister outposts. Six times the CCF had crossed over from Carson to Elko to try to retake the latter position, but had been thus far deterred by Allied firepower. Accordingly, at 2300, the 25th Division ordered its reserve 14th Regiment, earlier committed to the Elko-Carson counterattack, to withdraw from Elko and the Turks to pull back from Vegas to the MLR. By daybreak the withdrawal was completed and 25th Division and Turkish troops had regrouped on the MLR.

The Army reported that more than 117,000 rounds of artillery and 67 close air support missions had buttressed the UNC ground effort. Official estimates indicated that in the three-day action the Chinese had fired 65,000 rounds of artillery and mortar, “up to this point an unprecedented volume in the Korean War.”433 The Marine artillery contribution from its four active battalions during this 28–30 May period totaled 56,280 rounds in 835 missions.

During the three-day siege, 15 to 33 Marine tanks poured their lethal 90mm projectiles on the enemy from MLR firing slots. At times the action was so heavy that the tanks were refueled on line. As they ran out of ammunition and fuel, “armored utility vehicles of the battalion, with a basic load of ammunition aboard, maneuvered beside the tanks in position and rearmed them on the spot,”434 to permit virtual uninterrupted tank firing. One Marine was killed in the action the first night. Although 4,162 rounds of Chinese fire fell near the tank positions, no damage to materiel was reported. For their part the M-46s and flames were responsible for 721 enemy deaths, an estimated 137 more killed, 141 wounded, and an estimated 1,200 injured.

During the second day of action, nearly 20 missions were flown by Corsairs and Skyraiders of the three Marine attack squadrons and the jet fighters of VMF-311 and -115. Altogether throughout 28–30 May, Marine aircraft had flown no less than 119 sorties for the inflamed sectors of the U.S. Army 25th Division and adjacent British 1st Commonwealth Division. Of these, 99 were in support of the sagging Carson-Elko-Vegas-Berlins line.

Ground action ceased the following day as rain drenched the battlefield, although the 11th Marines reported sightings of more than 200 Chinese soldiers, most of them on the three recently lost outposts. Benched while the fierce battle was going on, the 1st Marines remained under operational control of I Corps as a possible contingency force from 29 May to 5 June. On the latter date, following the Eighth Army decision not to retake the Carson-Elko-Vegas outposts, the regiment reverted to Marine control and returned to Camp Britannia. The previous day the Communists had agreed on all major points of the UNC final offer and it appeared that a ceasefire was close at hand.

Diplomats and military leaders both felt this latest Chinese assault was to show a strong military hand and win dominating terrain features along the MLR. Thus the enemy would be able to improve his defensive posture when final battlelines were adjusted at the truce. It was not believed that the CCF effort was an attempt to expand their operations into a general offensive. In any event, the Nevada positions were downgraded from their previous designation as major outposts. I Corps also decreed no further effort would be made to retake them and that a “revaluation of the terrain in view of the destruction of the defensive work indicates these hills are not presently essential to defense of the sector.”435

If things were now relatively quiet along the battlefront of the I Corps coastal sector, the situation had begun to heat up in the central part of the UNC defense line. On 10 June, following a CCF realignment of troops and supply buildup that had not gone unnoticed by Eighth Army intelligence officials, elements of the CCF 60th and 68th Armies struck the ROK II Corps area, on the east-central front. (See Map 29.) Advancing south along both sides of the Pukhan River with two divisions, the Chinese struck at the ROK II defense line which originally had bulged out to form a salient in the Kumsong vicinity. Within six days the ROK line had been forced back 4,000 yards. In subsequent assaults the enemy made new penetrations further west in the ROK II MLR. Although the main Communist thrust was directed against the ROK II Corps, secondary attacks were also made in the X Corps sector east of ROK II, in the Punchbowl area manned by the ROK 20th Division. It was the heaviest, all-out drive since the CCF spring offensive of April-May 1951, when the UNC had been pushed south approximately 30 miles across the entire Korean front.

By 18 June, the CCF assaults started to settle down. During the nine days of flaming action, ROK units had suffered some 7,300 casualties to enemy losses of 6,600. Boundaries had been redrawn and three ROK divisions had been redeployed in counterattacks to plug holes in the line that the Chinese had punched open. Nearly 15,000 yards of ROK front had been pushed 4,000 yards south and several hill positions east of the Pukhan had been lost.