Eastward, in the central mountains of Korea, aerial observation on 8 July, the day Chonan fell, showed that enemy armor, truck, and infantry columns were moving south and were already below Wonju. This led to speculation at the Far East Command that the North Koreans were engaged in a wide envelopment designed to cut the main north-south line of communications in the Taejon area. South of the Han River only one enemy division, the 6th, initially was west of the Seoul-Pusan highway.
The area defended by the ROK Army after American troops of the U.S. 24th Division entered action on 5 July was everything east of the main Seoul-Taegu railroad and highway. In the mountainous central part of Korea there are two main north-south axes of travel and communication. The first, from the west, is the Wonju – Chungju – Mungyong-Kumchon corridor running almost due south from Wonju. The second, farther east, is the Wonju-Chechon-Tanyang-Yongju-Andong-Uisong-Yongchon corridor slanting southeast from Wonju.
The critical military terrain of both corridors is the high watershed of a spur range which runs southwest from the east coastal range and separates the upper Han River on the north from the upper Naktong on the south. Both rivers have their sources in the western slope of the Taebaek Range, about twenty miles from the Sea of Japan. The Han River flows south for forty miles, then turns generally northwest to empty into the Yellow Sea; the Naktong flows first south, then west, then again south to empty into the Korea Strait. Mungyong is at the pass on the first corridor over the high plateau of this dividing watershed. Tanyang is on the south side of the upper Han and at the head of the long, narrow pass through the watershed on the second corridor.
On the south side of this watershed, and situated generally at its base, from southwest to northeast are the towns of Sangju, Hamchang, Yechon, and Yongju in the valley of the Naktong. Once these points were reached, enemy units could turn down that valley for a converging attack on Taegu. Or, the more eastern units could cross the relatively wide valley of the Naktong to enter another east-west spur range of the southern Taebaeks at a number of points —the most important being Andong—and cut across to the east-west corridor between Taegu and Pohang-dong and the Kyongju corridor leading south to Pusan.
After the initial success of the North Korean Army in driving ROK forces from their 38th Parallel positions, the South Koreans east of the U.S. 24th Division were badly disorganized and fighting separate regimental and division actions. In the first part of July the ROK Army was generally disposed from west to east as follows: 17th Regiment, 2nd, Capital, 6th, and 8th Divisions, and the 23rd Regiment of the 3rd Division.
The North Korean Army advanced southward on a wide front. The N.K. 1st Division followed the 4th and the 3rd south out of Seoul, but then turned off on the next major road east of the Seoul-Pusan highway. This led through Ichon and Umsong. Ahead of it was the N.K. 2nd Division which had moved westward to this road after the fall of Chunchon. At Ichon, ROK forces cut off an enemy regiment and destroyed or captured many mortars and several pieces of artillery. Farther west on the Yongin road another enemy regiment suffered heavy casualties at the same time, on or about 5 July, the day of Task Force Smith’s fight at Osan. After these actions, the N.K. 1st Division left the path of the 2nd and slanted southeast toward Chungju. This left the 2nd the first division east of U.S. 24th Division troops on the Seoul-Taejon highway and in a position to join with the N.K. 4th and 3rd Divisions in a converging attack on Taejon.
Despite losses and low morale among its troops, officers drove the 2nd Division southward toward ChInchon, twenty miles east of Chonan. There on 9 July, one day after Chonan had fallen, the ROK Capital Division and South Korean police ambushed one of its battalions, capturing four pieces of artillery and twenty-seven vehicles. This began a three-day battle between the enemy division and the ROK Capital Division.
The ROK’s withdrew on 11 July after other enemy divisions had outflanked them on the west by the capture of Chonan and Chonui. The N.K. 2nd Division, exhausted and depleted by heavy casualties, then entered ChInchon. Despite its condition, its commander allowed it no rest and drove it on toward Chongju , headquarters of the ROK I Corps. At the edge of the town, ROK artillery took it under fire and inflicted another estimated 800 casualties. Only when the ROK troops at Chongju were forced to fall back after the U.S. 24th Division, on 12 July, lost Chochiwon, twelve miles westward, did the enemy division enter the town.
Eastward, the N.K. 7th Division advanced down the mountainous central corridor of Korea after it had helped the 2nd Division capture Chunchon in the opening days of the invasion. Retiring slowly in front of it and fighting effectively was the ROK 6th Division. Between Chunchon and Hongchon, the 6th Division inflicted approximately 400 casualties on the enemy division and knocked out a number of its T34 tanks. From Hongchon the battle continued on F. Temple down the road toward Wonju, the action reaching the edge of that rail and road center on or about 2 July. There, the North Korean High Command relieved Major General Chon U, commander of the 7th Division, because his division was behind schedule in its advance. At the same time, the North Korean high command redesignated the 7th Division the 12th, and activated a new 7th Division. After the fall of Wonju on or about 5 July, the newly designated 12th Division split its forces—part going southeast toward Chechon, the remainder south toward Chungju.
These enemy operations in the mountainous central part of the peninsula were conducted by Lieutenant General Kim Kwang Hyop, commanding general of the North Korean II Corps, with headquarters at Hwach’on. On or about 10 July, the North Korean high command relieved him for inefficiency because his corps was several days behind its schedule, replacing him with Lieutenant General Kim Mu Chong.
Below Wonju, while the ROK 6th Division tried to defend the Chungju corridor, the ROK 8th Division upon arriving from the east coast tried to establish a line to defend the Tanyang corridor, the next one eastward. After seizing Chungju and Chechon, the N.K.12th Division converged on Tanyang and on 12 July encountered the ROK 8th Division just north of that village. The N.K. 1st Division, having entered the central sector from the northwest, turned south at Chungju and on the 12th approached positions of the ROK 6th Division just above Mungyong. The N.K.15th Division, meantime, joined the attack after following the 7th Division from Chunchon to Wonju. At Wonju, the 15th veered westward, passed through Yoju, then turned south, clearing the town of Changhowon-ni after a stiff battle with ROK forces. By 12 July, the 15th occupied Koesan, eighteen miles northwest of Mungyong.
The ROK 8th Division in its withdrawal from the east coast was supposed to concentrate in the vicinity of Wonju-Chechon. For several days the ROK Army headquarters had only vague and fragmentary information concerning its location. Eventually, in moving from Tanyang toward Chungju on Army order the division found the enemy blocking its way. Instead of trying to fight through to Chungju or to make a detour, the ROK 8th Division commander decided, in view of the exhaustion of his troops and the time involved in attempting a detour over mountain trails, that he would transfer the division to Chungju by rail on a long haul southward to Yongchon , thence to and through Taegu. A KMAG adviser found part of the division at Yongchon , between Pohang-dong and Taegu; other parts appear to have reached Taegu. The ROK Army issued new orders to the 8th Division which sent it back by rail to the upper Han River area. There on the south side of the upper Han River in the Tanyang area the 8th Division had concentrated by 10 July to defend the Yongju-Andong corridor.
American and ROK strategy and tactics in this part of Korea now centered on holding the Mungyong and Tanyang passes of the Han-Naktong watershed. Both offered excellent defensive terrain. The major part of the North Korean Army was striking in a great attack on a wide front against the southern tip of the peninsula. Five divisions moved south over the two mountain corridors; while a sixth followed a western branch of the first corridor, the road from Chongju through Poun to Hwanggan where it entered the Seoul-Taegu highway.
Over the first mountain corridor and across the Mungyong plateau came three North Korean divisions, the 1st, 13th, and 15th, supported by the 109th Tank Regiment of the 105th Armored Division.6 Over the second, or eastern, corridor came two North Korean divisions, the 12th and 8th. In the eastern mountains there were also 2,000-3,000 partisan guerrillas who had landed in the Ulchin area at the beginning of the war with the mission of operating as an advance element to prepare for the easy conquest of that part of South Korea. This group functioned poorly and was a big disappointment to the North Korean Army.
The battles in the mountains between the North and South Koreans in July were often bitter and bloody with losses high on both sides. One of the most critical and protracted of these began about the middle of the month near Mungyong between the N.K. 1st Division and the ROK 6th Division for control of the Mungyong pass and plateau.
On the next corridor eastward, the N.K. 12th Division carried the main burden of the attack all the way south from the Parallel to the upper Han River. Some of its advanced troops crossed the river on 12 July and the division captured the river crossing at Tanyang on the 14th. The 12th then fought the ROK 8th Division for control of the Tanyang Pass near the village of P’unggi, northwest of Yongju. It outflanked the ROK positions astride the road at Tanyang Pass and forced the 8th Division to withdraw southward. By the middle of July the North Koreans were forcing the Taebaek Mountain passes leading into the valley of the upper Naktong River.
On the east coast along the Sea of Japan the N.K. 5th Division and the 766th Independent Infantry Unit after crossing the 38th Parallel moved south with virtually no opposition. The high and all but trackless Taebaek Range, with almost no lateral routes of communication through it, effectively cut off the east coast of Korea below the 38th Parallel from the rest of the country westward. Geography thus made it an isolated field of operations.
At Kangnung, on the coastal road, twenty miles below the Parallel, the 11th Regiment of the 5th Division swung inland on an 8-day 175-mile march through some of the wildest and roughest country in Korea. It passed through Pyongchang, Yongwol, and Chunyang. At the last place the regiment met and fought a hard battle with elements of the ROK.
Reports of strong unidentified enemy or guerrilla forces moving south along the Taebaek Range now reached the ROK Army and 24th Division headquarters. They assumed that these forces intended to attack Pohang-dong in conjunction with the main enemy force moving down the coastal road.
Colonel “Tiger Kim,” feeling the force of the N.K. 5th Division for the first time, requested that he be sent reinforcements. Colonel Emmerich, senior KMAG adviser with the ROK 3rd Division, in turn requested that the ROK Army release immediately the ROK 1st Separate Battalion and the Yongdungpo Separate Battalion from their anti-guerrilla operations in the Chiri Mountains of southwest Korea. This was granted and the two battalions, numbering about 1,500 men armed with Japanese rifles and carbines, moved by rail and motor transport to the east coast.
Meanwhile, Captain Harold Slater, KMAG adviser with the ROK 23rd Regiment, sent to Colonel Emmerich at Taegu a radio message that the ROK situation near P’yonghae-ri had grown critical. Emmerich started for that place accompanied by the G-3 of the ROK 3rd Division. Some fifty miles below the front, at Pohang-dong, they found retreating ROK soldiers. They also found there the regimental executive officer in the act of setting up a rear command post. Emmerich, through the ROK G-3, ordered them all back north to Yongdok and followed them himself.
Already U.S. naval and air forces had joined in the fight along the coastal road. Ships came close in-shore on the enemy flank to bombard with naval gunfire the North Korean troop concentrations and supply points on the coastal corridor. The newly arrived 35th Fighter Group at Yonil Airfield joined in the fight. Weather permitting, aircraft bombed and strafed the N.K. 5th Division daily. Captain Gerald D. Putnam, a KMAG adviser with the ROK 23rd Regiment, served as an observer with the fighter group in identifying targets and in adjusting naval gunfire. Heavy monsoon rains created landslides on the mountain-flanked coastal road and helped to slow the North Korean advance.
Late in the afternoon of 11 July the command post of the ROK 23rd Regiment withdrew south into Yongdok. When the 3rd Division commander arrived at Pohang-dong, pursuant to Colonel Emmerich’s request that he take personal command of his troops, he ordered the military police to shoot any ROK troops found in the town. That proved effective for the moment. The next day, young Brigadier General Lee Chu Sik arrived on the east coast to assume command of the division.
On or about 13 July, the N.K. 5th Division entered P’yonghae-ri, twenty-two miles above Yongdok and fifty miles from Pohang-dong. There the 10th Regiment turned westward into the mountains and headed for Chinbo, back of Yongdok. The enemy advances down the mountain backbone of central Korea and on the east coast had assumed alarming proportions. The attack on Yongdok, the first critical and major action on the east coast, was at hand.
General Dean tried to give this front additional strength by assembling there the advanced units of the 25th Infantry Division, commanded by Major General William B. Kean. It was the second United States division to be committed in the war and arrived in Korea between 10 and 15 July. On the 8th, General Kean and an advance party flew from Osaka, Japan, to Taejon for a conference with General Dean. Two days later the 27th Infantry Regiment (Wolfhound) landed at Pusan. There the regiment learned that its new commander was Lieutenant Colonel John H. “Mike” Michaelis. On the 12th, a second regiment, the 24th Infantry, an all-Negro regiment and the only regiment in the Eighth Army having three battalions, arrived in Korea. Colonel Horton V. White commanded it. Lastly, the 35th Infantry Regiment, commanded by Colonel Henry G. Fisher, arrived at Pusan between 13 and 15 July.
The 27th Infantry at first went to the Uisong area, thirty-five miles north of Taegu. General Kean opened his first 25th Division command post in Korea at Yongchon , midway between Taegu and Pohang-dong. On 12 July General Dean ordered him to dispose the 25th Division, less one battalion which was to secure Yonil Airfield, so as to block enemy movement south from Chungju. One regiment was to be in reserve at Kumchon ready to move either to the Taejon or the Chongju area. The next day, 13 July, the 27th Infantry moved from Uisong to Andong on Eighth Army orders to take up blocking positions north of the town behind ROK troops.
On 13 July, with the U.S. 24th Division in defensive positions along the south bank of the Kum River, the front extended along that river to a point above Taejon, eighty miles south of Seoul, where it bent slightly north of east to pass through Chongju and across the high Taebaek passes south of Chungju and Tanyang, and then curved slightly south to the east coast at Pyonghae-ri, 110 air miles north of Pusan at the southern tip of the peninsula. On all the principal corridors leading south from this line heavy battles were immediately in prospect.
SOURCE: South to the Naktong, North to the Yalu; BY: Colonel Roy E. Appleman (United States Army Center of Military History)