General Ridgway was on hand for the planning conference held on 19 February in General Moore’s CP at Yoju and attended by officers from IX and X Corps. General Smith, Colonel McAlister, and Colonel Bowser represented the 1st Marine Division.
The scheme of maneuver called for the Marines to relieve elements of X Corps and attack in a northeasterly direction from a line of departure north of Wonju ([Map 6]) through the Wonju basin. The object was to cut off enemy forces which had penetrated south and east of Hoengsong, and to recover control of the roads running eastward by seizing the high ground just south of the town.[91]
[91] 1stMarDiv HD, Feb 51, 1–2, 20.
In the X Corps zone to the east, on the right flank of the Marines, the 7th Infantry Division was to attack to the north along the Yongwol-Pyongchang road. On the other Marine flank would be elements of the 6th ROK Division.
Simultaneous advances were planned for I Corps to the west, where patrols had found evidence that Seoul was lightly held.
Two U.S. Army units were designated at the 19 February conference to support the 1st Marine Division—the 74th Truck Company and the 92d Armored Field Artillery, then en route to the Chungju area.[92] These cannoneers and their commanding officer, Lieutenant Colonel Leon F. Lavoie, USA, were well and favorably known to the Marines, having given effective support during the Chosin Reservoir operations.
[92] Ibid.
First Marine Division OpnO 6-51, issued on 20 February, directed the two assault regiments, the 1st and 5th Marines, to jump off at 0800 on the 21st and seize the first objective, the ridgeline about three and a half miles south of the high ground dominating Hoengsong ([Map 6]). RCT-1, with Division Recon Company and C/Engineers attached, was to pass through elements of the 2d Infantry Division in zone while RCT-5, with A/Engineers attached, passed through elements of the 187th Airborne Infantry, USA. RCT-7 had been designated the reserve regiment; but since it could not arrive from the Pohang-Andong area in time, a battalion of the 5th Marines was assigned this mission.[93]
[93] Ibid., 2, 22, and 1stMarDiv OpnO 6-51.
The objective area was believed to be defended by the 196th Infantry Division of the 66th CCF Army and unknown elements of the 39th and 40th CCF Armies. Ahead of the Marines and other IX Corps units lay some uninviting terrain. Rocky heights and narrow valleys were laced by swift streams, the largest being the river Som, running from northeast to southwest through a defile cutting across the western part of the Division sector. Bordering this twisting stream was the Wonju-Hoengsong “highway”—a poor dirt road even by Korean standards. Through the right half of the Division zone an even more primitive road, scarcely fit for vehicular traffic, wound northeast from Wonju.[94]