 Patch initiated a new offensive just as the 38th Division began to withdraw from the inland ridges and hills that it had occupied . On 20 January , the 25th Infantry Division , under Major General J. Lawton Collins , attacked several hills , designated Hills 87 , 88 , and 89 by the Americans , that formed a ridge that dominated Kokumbona . Encountering much lighter resistance than anticipated , the Americans seized the three hills by the morning of 22 January . Shifting forces to exploit the unexpected breakthrough , Collins quickly continued the advance and captured the next two hills , 90 and 91 , by nightfall , placing the Americans in position to isolate and capture Kokumbona and trap the Japanese 2nd Division . 
