This study is an operational and tactical study of a battle fought by the U. S. 1st Marine Division near "the Punchbowl," an extinct volcano of military value in the Taebaek Mountains of Korea, from late August through mid September 1951. That engagement was to be the last 1st Marine Division offensive of the Korean War. This battle, for Yoke and Kanmubong Ridges, has received little coverage from historians. That it is all but forgotten is surprising, since it was one of the hardest fought for United States Marines in the war. The casualties were high, and Americans did not understand why so many had to die for a war that seemed to already be set to conclude by negotiations. This study tells the story of that battle more completely than ever before, and assesses its significance to the course of the Korean War.