"Okanogan" rejoined the US Pacific Fleet upon the outbreak of the Korean War, and in August 1950, loaded part of the 1st Marine Division at San Diego for Japan. These troops had been urgently requested by General Douglas MacArthur for a counter-offensive against North Korean aggression. "Okanogan" landed the men at Inchon 15 September, in an amphibious assault of incredible difficulty. The skill with which the operation was executed won acclaim from General MacArthur, who exclaimed "...the Navy and Marine Corps have never shone brighter …". "Okanogan" landed men of the same division in the assault on Wonsan 26 October.