PUSH TO THE EAST
23d Infantry Regiment, 4–8 April 1951
Before Operation Courageous ended, General Ridgway ordered a further advance. Intelligence reports indicated the enemy was preparing for a general offensive but was not yet ready to attack. Ridgway decided that a continuation of the movement forward to Line Kansas, a phase line north of the 38th parallel that ran generally east from the Imjin River through the Hwach’on Reservoir to the east coast, would destroy additional enemy forces and supplies, position UN troops on defensible terrain, and facilitate, if desired, a further advance in the center to threaten the enemy’s key logistical area in the so-called Iron Triangle bounded by the towns of Ch’orwon, P’yonggang, and Kumhwa. These actions might seriously disrupt Chinese preparations for their offensive. The advance to Line Kansas, scheduled to begin 3 April, was named Operation Rugged; the subsequent limited movement toward the Iron Triangle was designated Operation Dauntless.
The U.S. I and IX Corps began Operation Rugged on 3 April against mixed opposition. In the west, the advance reached the heights south of the Hant’an River on 6 April, but the IX Corps in the center was slowed by strong delaying forces three miles short of the Hwach’on Reservoir. In X Corps, for Operation Rugged, the corps’ western boundary was shifted to the left, and the U.S. 2d Infantry Division was ordered to extend to the west and relieve the IX Corps’ 1st Marine Division. The 2d Division’s 23d Infantry Regimental Combat Team (RCT) played a key role in the ensuing operations.