Marines’ central sector; American and ROK counterattacks eliminated this penetration near dawn, and the 115th made no further attempt to take the dam or town. Eager to close ranks as the IX Corps' front quieted after daylight on the 23rd, General Hoge ordered the ROK 6th Division to occupy positions on the Kansas Line, north of the area in which General Chang was reassembling his forces. The 1st Marine Division was to pull back against the Pukhan River to a line anchored near the Hwacheon Dam and curving southwest to a juncture with the ROK. Manning the long curve would require the commitment of the entire 1st Marine Division, and even then he would not be able to set up a solid front. General Chang faced no small task in recovering troops who had scattered east and west into adjacent sectors, reorganizing his entire division, and then moving his nervous forces north toward the PVA. But the adjustments, if achieved, would retain control of the Hwach’on Dam, eliminate the Marines’ open left flank, and join the two IX Corps divisions with a minimum of movement. Cheorwon and Kumhwa (22–23 April) At the right of US I Corps, the PVA 59th Division, 20th Army, though kept under artillery fire while massing in the Kwandok-san ridges below Kumhwa, struck hard at the center of the US 24th Infantry Division. Leading forces opened a gap between the 19th and 5th Infantry Regiments; reinforcements widened the attack but concentrated on movingthrough the gap and down a ridge behind the inside battalion of the 19th Infantry. Pressure on the adjacent battalion of the 5th Infantry forced it to withdraw almost . Quick to follow, the PVA reengaged the battalion within an hour. Regimental reserves took up blocking positions on the flanks of the PVA penetration and helped to confine it, but General Blackshear M. Bryan’s attempt to move part of his reserve 21st Infantry Regiment from the Kansas Line north onto high ground at the point of penetration failed when PVA occupied the ground first. By daylight the PVA drove almost through the center of the division. Bryan withdrew his line regiments down the sides of the PVA wedge into positions below it, where, though kept under pressure at center, they were able to stand. Meanwhile, on learning of the ROK 6th Division's retreat on his right, Bryan set the 21st Infantry in blocking positions