As the Eighth Army in Korea advanced toward the 38th parallel in Operation RIPPER in early March, 1951, General Ridgway looked ahead to the enemy supply and communications center of Chunchon, which he expected the enemy to defend stubbornly. In order to loosen the defense, he alerted the 187th Airborne RCT for a drop there on 22 March. But when UN armored patrols entered Chunchon on the 19th, it became apparent that UN progress and enemy withdrawal had been too rapid for a profitable airborne operation. The project was cancelled.
With Seoul in UN hands, Ridgway enlarged RIPPER to include an advance westward to the Imjin River. The I corps began that attack on 22 March. In order to block enemy withdrawal from Seoul toward Kaesong, to trap large numbers of enemy troops, and to facilitate the I Corps advance to the Imjin, about 3,000 men of the 187th Airborne RCT and the 2nd and 4th Ranger Companies parachuted on 23 March- after a one-day postponement- onto drop zones at Munsan-ni, about 20 miles northwest of Seoul. There was little opposition.
On the same day, 23 March, an armored column, Task Force Growden, started forward to make contact with the airborne troops. Against very little resistance, the task force covered the 15 intervening miles and reached Munsan-ni on the 24th.
The airborne operation had failed to block the enemy withdrawal or to trap enemy units, but it facilitated the advance to the Imjin River.
With the 187th Airborne RCT at Munsan-ni now on the west flank of an enemy-held area, the I Corps ordered the paratroopers and Rangers to attack due east. By capturing domination ground about 15 miles east of the drop zone behind the enemy front, the Americans would facilitate advance of the U.S. 3rd Division, which was to crush the enemy against the paratroopers.
Bad weather and impassable roads forced the armored task force to return to Seoul and slowed the eastward movement of the airborne troops. By the time the 187th Airborne RCT reached its objective, the enemy was gone.