Battle of the Chosin Reservoir Battle of the Chosin Reservoir, Chosin also
called Changjin, campaign early in the Korean War, part of the Chinese Second Offensive
(November–December 1950) to drive the United Nations out of North Korea. The Chosin Reservoir
campaign was directed mainly against the 1st Marine Division of the U.S. X Corps, which
had disembarked in eastern North Korea and moved inland in severe winter weather to a
mountainous area near the reservoir. The campaign succeeded in forcing the entire X Corps to
evacuate to South Korea, but the Chinese did not achieve their particular objective of
isolating and destroying the 1st Marine Division. Instead, in a deliberate retrograde movement
that has become one of the most-storied exploits in Marine Corps lore, the Marines turned and
fought their way down a narrow vulnerable road through several mountain passes and a
bridged chasm until they reached transport ships waiting at the coast.
Crossing Into North Korea Following the successful landing of the X
Corps at Inch’ŏn in September 1950, the United Nations Command (UNC), under the direction
of U.S. Pres. Harry S. Truman’s administration and the UN General Assembly, pursued the remnants
of the communist Korean People’s Army into North Korea. On the orders of Gen. Douglas
MacArthur, commander of all allied forces in the UNC, the U.S. Eighth Army crossed the
38th parallel (the prewar border) on October 7 and advanced up the western side of the
Korean peninsula toward P’yŏngyang, the capital of the Democratic People’s Republic
of Korea. At the same time, MacArthur redeployed the X Corps on amphibious ships around the
peninsula to Korea’s east coast. The X Corps (commanded by Maj. Gen. Edward M. Almond)
included the 1st Marine Division (Maj. Gen. Oliver P. [“O.P.”] Smith), the 7th Infantry
Division (Maj. Gen. David G. Barr), and the 3rd Infantry Division (Maj. Gen. Robert H.
Soule). The corps also had control of the Capital and 3rd divisions of the South Korean
I Corps, which was already crossing the 38th parallel on the east coast highway.
What MacArthur did not know was that the Chinese had feared such an offensive since the Inch’ŏn
landing. The Chinese began preparations to enter the war by sending supplies and support
troops into North Korea. Meanwhile, Chinese combat divisions, some 21 in number but expanding
to 33 by December, remained in Manchuria ready to move against the UNC ground forces. On
October 18–19, Chinese leader Mao Zedong, after considerable debate, ordered the Chinese
People’s Volunteers Force (CPVF), under the command of General Peng Dehuai, to move
against the Eighth Army, whose lead elements had advanced beyond P’yŏngyang and were
marching along two separate routes toward the border with China at the Yalu River.
The Chinese First Offensive of October 25–November 6 staggered the Eighth Army, damaging one
American division and four South Korean divisions in the battle of Onjŏng-Unsan. To the east,
two American divisions of the X Corps had landed on October 26 and 29, and the South
Korean I Corps was heading north up the coast road toward the Sino-Soviet border. The wide
separation of these units made them a tempting objective for the Chinese. On November 2–4,
the South Koreans and U.S. Marines fought their first engagement against the Chinese
at Sudong, inland from the port city of Hŭngnam. There a Marine regiment defeated an attacking
division, killing at least 662 Chinese soldiers. Advancing To Chosin
Underestimating the fighting ability of the CPVF, MacArthur ordered Almond to advance
inland with the 1st Marine and 7th Infantry divisions to the Chosin Reservoir. From there
the two divisions would move west toward Kanggye, a mountain mining town where the Chinese and
North Korean armies seemed to be concentrating—a maneuver that would place the X Corps north
of and behind the CPVF armies facing the Eighth Army. MacArthur’s scheme required an 88-km
(55-mile) advance over a single unpaved road through the heart of the T’aebaek Mountains
in freezing weather and blinding snowstorms. Smith told Almond the plan was rash, but Almond,
operating directly under MacArthur, ordered the Marines forward.
The X Corps’ first objective, the village of Hagaru-ri, rested near the southern tip
of the reservoir, a narrow mountain lake that provided hydroelectric power to the mining
industries of northern Korea. The lake’s proper name is the Changjin Reservoir, but,
during Japan’s annexation of Korea (1910–45), its name had been changed to Chōsen, the
Japanese name for Korea. Through successive translations and hurried mapmaking, the reservoir
became known as Chosin and remains so to this day for American veterans of the Korean War.
By any name it was a cold barren battleground where deep foxholes could be dug into the
frozen earth only with the help of explosives and bulldozers.
With its supplies moving by truck, the 1st Marine Division established battalion-sized
bases at Chinhŭng-ni and Kot’o-ri, villages along the Main Supply Route (MSR), the X Corps’
name for the road to the reservoir. The division began its final march to the reservoir on
November 13, with two of its reinforced regiments, the 7th and 5th Marines, in column and moving
cautiously. Each regiment was a regimental combat team with attached artillery battalions,
a tank company, engineers, and headquarters and service units. On November 15 lead elements
of the 7th Marines reached Hagaru-ri. From there the regiment prepared for its next advance,
west of the reservoir to Yudam-ni, 22 km (14 miles) away, while the 5th Marines moved cautiously
up the reservoir’s right bank.
General Smith, unhappy with this risky deployment, persuaded Almond to allow the Marines to concentrate
at Hagaru-ri and replace the eastern force with a unit from the 7th Infantry Division.
Almond ordered General Barr to form a regimental combat team of two infantry battalions, an
artillery battalion, and other troops. The 31st Infantry Regiment, commanded by Col.
Allan D. MacLean and known as Task Force MacLean, numbered 3,200 Americans and Koreans. It replaced
the Marines east of the reservoir on November 25. Smith used this operational pause to strengthen
the defenses of Hagaru-ri and build a rough airfield for emergency resupply and medical
evacuations. A battalion of Marines manned the most vulnerable part of the perimeter,
but much of the position had to be manned by noninfantry units. The Marine Corps’
investment in making “every Marine a rifleman” would soon pay dividends.
The Chinese Strike As the 1st Marine Division advanced, Peng
ordered the uncommitted Ninth Army Group (commanded by General Song Shilun) to leave Manchuria
and destroy it. Song’s army group (12 divisions in 3 armies) numbered 150,000 soldiers—mostly
infantry with mortars and machine guns but not much artillery, since the Chinese lacked
guns, shells, and trucks and feared UNC air strikes on road-bound columns. Moreover, the
army group had not prepared for winter war. Still, Mao found the X Corps too tempting
a target to resist, and the Chinese believed they had found an effective formula for fighting
the UNC: stealth, nighttime attacks, ambushes, local surprise, and superiority in numbers.
The Ninth Army Group moved into positions on either side of the reservoir with five
divisions, and it moved three more divisions to cut the road south of Hagaru-ri and attack
Kot’o-ri. Smith, benefiting from aggressive intelligence operations, knew the Chinese
had massed around his division, but Almond did not share his alarm.
In the last week of November the Ninth Army Group launched simultaneous division-level
attacks on the 1st Marine Division at Yudam-ni, Hagaru-ri, and Kot’o-ri and on Task Force
MacLean east of the reservoir. The 7th and 5th Marines, having met major Chinese forces
in a daylight attack on November 27, quickly prepared a perimeter defense for night action.
The enclaves at Hagaru-ri and Kot’o-ri were even better prepared, though the Hagaru-ri
perimeter had too much critical hill terrain to defend with the available troops. Halfway
between Yudam-ni and Hagaru-ri, one Marine rifle company defended Tŏktong Pass, where
the Chinese 59th Division had placed a major roadblock. Task Force MacLean, meanwhile,
was strung out along the east shoreline road in seven different locations.
In three days of intense night battles and daylight probes starting on the night of November
27–28, all of the major Marine positions held, but Task Force MacLean did not. By the
time the surviving soldiers (minus their commanding officer, who went missing in action en route
and was never recovered) managed to struggle on foot and in small, disorganized groups
around the frozen reservoir or directly across the ice to Hagaru-ri, they numbered only 670,
and only half of them were fit for duty. The Marine regiments, on the other hand, though
reduced by one-third to one-half in their rifle companies, managed to halt or curb the
Chinese attacks, aimed at penetrating the perimeters and overrunning artillery positions,
the airfield, and command posts. Artillery fire around the clock and air strikes during
the day also punished the Chinese. The only real misstep in the defensive battle was a
decision by Smith and the 1st Marine Regiment commander, Col. Lewis B. (“Chesty”) Puller,
to send a convoy of tanks and supply trucks from Kot’o-ri to Hagaru-ri on November 29.
Task Force Drysdale, commanded by Lieut. Col. Douglas B. Drysdale, 41 Independent Commando,
Royal Marines, in addition to service and headquarters troops, included a Marine infantry
company, an army infantry company, and Drysdale’s British raiding battalion. The task force
was ambushed en route. One-third of the force (tanks and infantry) fought through to Hagaru-ri,
and another third fought its way back to Kot’o-ri. The remainder (162 officers and men) died
or became captives. Fighting Back To The Coast
On November 29 Almond, having met with MacArthur in Tokyo, acknowledged that the X Corps could
survive only if its dispersed divisions headed for the nearest port. Most headed to Hŭngnam
and were evacuated to Wŏnsan—a decision that reflected the Eighth Army’s defeats
in the west. Moreover, the Truman administration soon discarded the policy of unifying Korea
by force, though it still wanted to save the Republic of Korea. Preserving the UNC for
this mission (its original one) dictated that the X Corps escape the grasp of the CPVF Ninth
Army Group. To achieve this aim, Almond took a worst-case position: the Yudam-ni and Hagaru-ri
garrisons would rally at the latter perimeter and then fly out, abandoning the division’s
heavy weapons, vehicles, and supplies. The rest of the division would march back down
the MSR from Kot’o-ri to Hŭngnam. Smith, however, refused to abandon his division’s
equipment. Instead, he argued that the Yudam-ni–Hagaru-ri movement was the critical one. Once the two
groups had united at Hagaru-ri, they could absorb ammunition and replacements by air
and evacuate the worst wounded and frozen casualties. At that point the division could
turn and fight its way to the coastal plain—“advancing in a different direction,” as Smith phrased
it. Almond conceded that such a withdrawal by the 1st Marine Division would attract Chinese
divisions and thus allow the rest of the X Corps to retreat without real danger.
On December 1 the 1st Marine Division began the movement that eventually took its rear
guard inside the perimeter established by the 3rd Infantry Division near Hŭngnam. In
the course of this escape, the division rendered three more Chinese divisions ineffective in
addition to the four that had already been ruined at Yudam-ni and Hagaru-ri. The Yudam-ni
group, the first to move out, did not stop until it reached Hagaru-ri on December 4.
The 5th Marines walked the road to protect the vehicle train, while the 7th Marines plodded
through the hills to break up Chinese “fire sacks” and relieve the Tŏktong Pass defenders.
Their two artillery battalions, meanwhile, moved by bounds to ensure continuous fire
support, and Marine and navy fighter-bombers were on call during daylight to strike any
suspected ambush. The arrival of the 5th and 7th Marines at Hagaru-ri ensured that the
airfield would not be closed by Chinese fire. Marine and air force transports brought in
critical ammunition and gasoline and took out 4,500 casualties. The fuel was critical:
one Marine artillery battalion lost half its guns north of Hagaru-ri when its tractors
ran out of diesel fuel. The reassembled 1st Marine Division reorganized,
tried to eat and sleep in warming tents, and prepared to fight south to the coast. On December
6 the “attack in a different direction” continued, destination Kot’o-ri, 18 km (11
miles) distant. The real challenge was Funchilin Pass below Kot’o-ri, where the Chinese had
destroyed a bridge over a chasm. The solution was to assemble a bridge that was air-dropped
in sections, enough of which survived to allow vehicles to pass. The Chinese contested the
withdrawal at this chokepoint, but the Marines fought through the trap, although the rear
guard had to abandon seven tanks. The final potential barrier, another pass to the south,
had been cleared by the 1st Battalion, 1st Marines, in a nighttime attack in temperatures
as low as −34 °C (−30 °F). A battalion of the 3rd Infantry Division stopped two attacks
on the final Hŭngnam perimeter on December 3 and 15. By the latter date the 1st Marine
Division, its rear guard having reached Hŭngnam on December 11, had been loaded onto their
waiting transport ships. Resistance by the Chinese had become almost token, their troops
ruined by cold, starvation, and relentless X Corps firepower.
The Chosin Reservoir campaign was a geographic victory for the Chinese, for the X Corps,
instead of redeploying to Wŏnsan, was forced to return to South Korea, where it became
part of the Eighth Army in January 1951. Nevertheless, the campaign ruined the CPVF Ninth Army Group,
which did not return to the front until March 1951, and it convinced the UNC that allied
ground troops could defeat Chinese armies, however numerous. The Chinese have remained
vague on their losses in the battle, but their own records and UNC estimates put the Ninth
Army Group’s casualties in the range of 40,000 to 80,000, when one counts combat deaths
and wounded plus deaths and incapacity from the cold. The 1st Marine Division lost 4,385
men to combat and 7,338 to the cold. Other X Corps losses amounted to some 6,000 Americans
and Koreans.