Key Facts
- Duration
- August 15 – September 19, 1950 (35 days)
- Times hill changed hands
- 20
- KPA unit engaged
- KPA 6th Division
- US regiments deployed
- 24th Infantry Regiment, 5th Infantry Regiment
- US division
- 25th Infantry Division
Strategic Narrative Overview
The US 25th Infantry Division deployed its 24th and 5th Infantry Regiments on Sobuk-san to defend its two key peaks. From August 15 to September 19, 1950, the engagement became a protracted stalemate, with Hill 665 — dubbed 'Battle Mountain' — changing hands 20 times. Neither side could secure a decisive hold on the summit, but UN forces consistently disrupted KPA efforts to push beyond the mountain toward Masan.
01 / The Origins
In the summer of 1950, North Korean People's Army forces pushed deep into South Korea following the June invasion, threatening to overrun the last UN defensive line around the Pusan Perimeter. The KPA 6th Division advanced toward Masan in the southwest, making the Sobuk-san mountain area — dominated by peaks P'il-bong and Hill 665 — a critical defensive position for the US 25th Infantry Division tasked with holding the sector.
03 / The Outcome
Although no side achieved a clear tactical dominance over the mountaintop, the battle ended as a UN strategic victory. US and ROK troops succeeded in their core mission of preventing the KPA 6th Division from advancing beyond Battle Mountain. This contributed to the broader stabilization of the Pusan Perimeter, setting conditions for the KPA's eventual defeat and withdrawal from the region.
Belligerents & Mobilization Analysis
Side A
1 belligerent
Side B
2 belligerents
Kinetic Engagement Axis
Scroll horizontally to view full axis. Events plotted relatively.