The deployment of the 45th Division set it against the US 23rd Infantry Regiment, 2nd Infantry Division at the edge of the reservoir above Yanggu and the 17th and 32nd Infantry Regiments of the 7th Infantry Division in the adjacent ground to the east. On the opposite wing of the KPA effort, the KPA 6th Division faced the ROK 3rd Division. At center, the 12th Division was poised for an attack in a zone straddling the US X Corps-ROK III Corps boundary and leading directly to Inje. During the afternoon of 22 April, IX Corps' airborne artillery observers located and brought down fire on a large enemy force concentrated ahead of the ROK 6th Division. Anticipating an attack, General Chang halted his division's advance toward the "Wyoming Line" about 16:00 and ordered his forward regiments, the 19th and 2nd, to develop defensive positions tied in with each other and with the 24th Division and 1st Marine Division on their respective outside flanks. Chang moved his reserve 7th Regiment into supporting positions immediately behind the 2nd Regiment, ahead of which more enemy forces had been observed than ahead of the 19th Regiment. Placing reserves so close to the front went against the recommendation of his Korean Military Advisory Group (KMAG) adviser, but Chang intended that this show of support would counter uneasiness that had begun to spread among his line forces at word of a probable PVA attack. IX Corps' commander General William M. Hoge moved three Corps' artillery units forward during the afternoon to help the 1st Marine Division and, in particular, to reinforce the support being given the ROK 6th Division by the New Zealand artillery; Company C, 2nd Chemical Mortar Battalion; and the division's own 27th Field Artillery Battalion. The Corps' latest ground gains had opened Route 17 in the 1st Marine Division's sector far enough north to allow use of a twisting, narrowly confined valley road branching west off Route 17 near the village of Chich’on-ni into the ROK 6th Division's rear area. The 92nd Armored Field Artillery Battalion moved up Route 17 and out the minor road to the west edge of the Marine sector from where its 155mm. self-propelled howitzers could support both the Marines and the ROk. The 987th Armored Field Artillery Battalion and 2nd Rocket Field Artillery Battery, both equipped with 105mm. howitzers, used the winding valley road to reach the right half of the ROK sector, where they took position behind the 7th Regiment near the ROK artillery and US 4.2-inch mortars.