The Battle of Ka-san was an engagement between United Nations Command (UN) and North Korean forces early in the Korean War from September 1 to September 15, 1950, in the vicinity of Ka-san (Ka mountain), Chilgok County in South Korea. It was a part of the Battle of Pusan Perimeter, and was one of several large engagements fought simultaneously. The battle ended in a victory for the United Nations after large numbers of United States Army (US) and Republic of Korea Army (ROKA) troops repelled a strong Korean People's Army (KPA) attack.
Attempting to capture Taegu as part of the Great Naktong Offensive, the KPA 1st and 13th Divisions advanced to the hill masses north of the city where they confronted the US 1st Cavalry Division and the ROKA 1st Division. The KPA sought to occupy a number of hill masses, most prominently Hill 902, known to South Koreans as Ka-san, for the ancient fortress situated atop it.
In two weeks of fighting in and around the fortress, the KPA were able to gradually push back the UN forces from Ka-san and Hills 755 and 314 to the south, but the UN forces held out strongly and the KPA were not able to quickly consolidate their gains. The UN forces defended the ground tenaciously, even assigning a battalion of engineers to fight on the front lines, eventually preventing the KPA from advancing long enough for the KPA to be outflanked by the Inchon landings on 15 September and on 16 September the UN forces began their breakout from the Pusan Perimeter which drove the KPA from the area.
Background Pusan Perimeter
From the outbreak of the Korean War and the invasion of South Korea by the North, the KPA had enjoyed superiority in both manpower and equipment over both the ROKA and the UN forces dispatched to South Korea to prevent it from collapsing. The KPA tactics were to aggressively pursue ROKA/UN forces on all avenues of approach south and to engage them aggressively, attacking from the front and initiating a double envelopment of both flanks of the unit, which allowed the KPA to surround and cut off the opposing force, which would then be forced to retreat in disarray, often leaving behind much of its equipment. From their initial June 25 offensive to fights in July and early August, the KPA used these tactics to effectively defeat any ROKA/UN force and push it south. However, when the ROKA/UN forces, under the Eighth United States Army, established the Pusan Perimeter in August, the ROKA/UN troops held a continuous line along the peninsula which KPA troops could not flank, and their advantages in numbers decreased daily as the superior UN logistical system brought in more troops and supplies to the UN forces.
When the KPA approached the Pusan Perimeter on August 5, they attempted the same frontal assault technique on the four main avenues of approach into the perimeter. Throughout August, the KPA 6th Division, and later the KPA 7th Division engaged the US 25th Infantry Division at the Battle of Masan, initially repelling a UN counteroffensive before countering with battles at Komam-ni and Battle Mountain. These attacks stalled as UN forces, well equipped and with plenty of reserves, repeatedly repelled KPA attacks. North of Masan, the KPA 4th Division and the US 24th Infantry Division sparred in the Naktong Bulge area. In the First Battle of Naktong Bulge, the KPA division was unable to hold its bridgehead across the river as large numbers of US reserve forces were brought in to repel it, and on August 19, the KPA 4th Division was forced back across the river with 50 percent casualties. In the Taegu region, five KPA divisions were repulsed by three UN divisions in several attempts to attack the city during the Battle of Taegu. Particularly heavy fighting took place at the Battle of the Bowling Alley where the KPA 13th Division was almost completely destroyed in the attack. On the east coast, three more KPA divisions were repulsed by the ROKA at P'ohang-dong during the Battle of P'ohang-dong. All along the front, the KPA troops were reeling from these defeats, the first time in the war their tactics were not working.
September push
In planning its new offensive, the KPA command decided any attempt to flank the ROKA/UN force was impossible thanks to the support of the UN naval forces. Instead, they opted to use frontal attack to breach the perimeter and collapse it as the only hope of achieving success in the battle. Fed by intelligence from the Soviet Union the North Koreans were aware the UN forces were building up along the Pusan Perimeter and that it must conduct an offensive soon or it could not win the battle. A secondary objective was to surround Taegu and destroy the UN units in that city. As part of this mission, the KPA would first cut the supply lines to Taegu.
On August 20, the KPA commands distributed operations orders to their subordinate units. The plan called for a simultaneous five-prong attack against the ROKA/UN lines. These attacks would overwhelm the ROKA/UN defenders and allow the KPA to break through the lines in at least one place to force the ROKA/UN forces back. Five battle groupings were ordered. The center attack called for the KPA 3rd, 13th and 1st Divisions to break through the US 1st Cavalry Division and ROKA 1st Division to Taegu.
Battle
Simultaneous with their attack at Ka-san, ROKA/UN and KPA units were similarly deadlocked a short distance away in the Battle of Tabu-dong. In that sector, KPA Major Kim Song Jun of the 19th Regiment, 13th Division had defected to the ROKA/UN side on September 1. He reported that a full-scale KPA attack was to begin at dusk that day. The 13th Division, he said, had just taken in 4,000 replacements, 2,000 of them without weapons, and was now back to a strength of approximately 9,000 men. Upon receiving this intelligence, 1st Cavalry Division commander Major general Hobart R. Gay alerted all of his division's front-line units to be prepared for the attack. ROKA 1st Division commander Major general Paik Sun Yup also braced his men for attack.
North Korean attack Hard on the heels of Kim's warning that the KPA attack would strike the night of September 2, the attack hit with full force in the Bowling Alley area north of Taegu. The attack caught the US 8th Cavalry Regiment unprepared at Sangju. The division was poorly deployed along the road to that town, lacking a reserve force to counterattack effectively. The KPA struck the 2nd Battalion, 8th Cavalry, the night of September 2–3 on Hill 448 west of the Bowling Alley and north of Tabu-dong, and overran it. On the right, E Company, although not under attack, was cut off and had to withdraw. The commanding officer of the 3rd Battalion placed I Company in a blocking position just north of Tabu-dong astride the road. There, two KPA T-34 tanks and some infantry struck it at 02:00 on September 3. In this action, I Company suffered many casualties but repelled the attack. The overrun 2nd Battalion withdrew through the 3rd Battalion which had assembled hastily in a defensive position south of Tabu-dong. During the day, elements of the KPA 1st Division forced the 8th Cavalry I&R Platoon and a detachment of National Police from the Walled City of Ka-san on the crest of Hill 902 (), east of Tabu-dong. On September 3, therefore, the UN command, the Eighth United States Army lost both Tabu-dong and Hill 902, the dominant mountain-top north of Taegu.
The North Koreans now concentrated artillery north of Hill 902 and, although its fire was light and sporadic, it did cause minor damage in the 99th Field Artillery positions. This sudden surge of the North Koreans southward toward Taegu concerned the Eighth Army commander, Lieutenant general Walton Walker. Walker ordered an ROKA battalion from the Taegu Replacement Training Center to a position in the rear of the 8th Cavalry, and the 1st Cavalry Division organized Task Force Allen, to be commanded by Assistant Division Commander Brigadier general Frank A. Allen, Jr. This task force comprised two provisional battalions formed of division headquarters and technical service troops, the division band, the replacement company, and other miscellaneous troops. It was to be used in combat as an emergency force should the North Koreans break through to the edge of Taegu.
US counterattack on Ka-san
Eighth Army countered the KPA advance down the Tabu-dong road by ordering the 1st Cavalry Division to recapture and defend Hill 902. Hill 902 gave observation all the way south through Eighth Army positions into the city, and, in KPA hands, could be used for general intelligence purposes and to direct artillery and mortar fire. Hill 902 was too far distant from the Tabu-dong road to dominate it; otherwise it would have controlled this main communication route. The shortage of KPA artillery and mortar ammunition reduced the advantages the peak held as an observation point for the KPA.
Despite being popularly known as the "walled city," there was no walled city on the crest of Ka-san in 1950. Ka-san, or Hill 902, the mountain which differs from most high peaks in this part of Korea in having an oval-shaped semi-level area on its summit. This oval is a part of a ridge-like crest, varying from to in width, which slopes down from the peak at to approximately at its southeastern end. On all sides of this ridge crest the mountain slopes drop precipitously. In ancient times, Koreans had built a stone wall around the crest and had converted the summit into a fortress. Most of the summit in 1950 was covered with a dense growth of scrub brush and small pine trees. There were a few small terraced fields. Koreans knew Ka-san as the "Sacred Mountain". Near the northern end of the crest still stood the Buddhist Poguk Temple.
When the 1st Cavalry Division on August 29 assumed responsibility for the old ROKA 1st Division sector north of Taegu it sent a patrol from the I&R Platoon to the top of Ka-san. There the patrol found 156 National Police. There was some discussion between Gay and Walker about whether the 1st Cavalry Division or the ROKA 1st Division should have the responsibility for the mountain. Gay maintained that his understrength division with a front was already overextended and could not extend eastward beyond the hills immediately adjacent to the Tabu-dong road. Uncertainty as to final responsibility for Ka-san ended on the afternoon of September 3 after the KPA had seized the mountain.
Colonel Ernest V. Holmes, Chief of Staff of the 1st Cavalry Division, was notified that the 1st Cavalry Division had responsibility for the Walled City. Holmes replied he would send a company of engineers to Ka-san. Holmes ordered Lieutenant colonel William C. Holley, commanding officer of the 8th Engineer Combat Battalion, to report to Colonel Raymond D. Palmer, commanding the 8th Cavalry Regiment. That afternoon Palmer in his command post on the Tabu-dong road outlined to Holley and the commanding officers of D Company, 8th Engineer Combat Battalion, and E Company, 8th Cavalry, his attack plan to regain control of Ka-san. The Engineer company, commanded by First lieutenant John T. Kennedy, was to lead the attack, E Company following. Once the force had gained the crest and E Company had established itself in defensive positions, the Engineer company was to come off the mountain. Many of the men in D Company were veteran infantrymen who had fought in World War II.
That evening, D Company loaded into trucks traveled north to the assembly area through a heavy rain. On the way they met two truckloads of National Police going south, some of them wounded. These were the police who, together with the detachment of the I&R Platoon, had been driven off Ka-san that afternoon. After waiting in the rain awhile for orders, the Engineer company turned around and went back to camp.
Engineer attack