defenses in the next good system of high ground to the north located generally on an east-west line through Hongcheon. Presenting something of a barrier to this ground in the IX Corps' zone was the Hongcheon River, which flowed into the zone from the northeast to a bend below Hongcheon town, then meandered west to empty into the Pukhan. Colonel Tarkenton expected the KPA forces in the higher ridges to the east to withdraw to positions on line with those of the PVA in the IX Corps' zone but did not expect the KPA defending Seoul and the ground west of the city, all of whom were outside the zone of the Ripper advance, to abandon their positions along the Han. Tarkenton also believed that PVA/KPA forces were now prepared, or nearly so, to make some form of strong counter effort and that they well might open it out of the Hongcheon area when Ridgway's forces arrived in that region. But on this count, as well as in his estimate of enemy defensive plans, the continuation of Operation Ripper would prove Colonel Tarkenton in error. The evidence of a PVA/KPA buildup collected by the army intelligence staff was nonetheless valid. At the same time, it was incomplete and off the mark in the identification and location of units. KPA and PVA buildup What the intelligence staff had reported in mid-February as the entry of seven new PVA armies into Korea was largely the return of the three KPA corps and nine divisions that had withdrawn into Manchuria for reorganization and retraining the past autumn. Beginning in January, KPA VI Corps, with the 18th, 19th and 36th Divisions, crossed the Yalu River at Ch’ongsongjin, northeast of Sinuiju. Avoiding Route 1 in favor of lesser roads nearby, Corps' commander Lt. Gen. Choe Yong Jin took his divisions south into Hwanghae Province and assembled them in the Namch’onjom-Yonan area northwest of Seoul. On arriving there in mid-February, General Choe assumed command of the KPA 23rd Brigade previously stationed in the area to defend the Haeju sector of the Yellow Sea coast. Eighth Army intelligence identified and caught the southward movement of KPA VI Corps by 1 March but remained in the dark, even at midmonth, about the reentry of KPA VII and VIII Corps. Crossing the Yalu at Sinuiju in January, VII Corps, with the 13th, 32nd and 37th Divisions, proceeded across Korea