of Efate, New Hebrides, and Noumea, New Caledonia, before returning to San Francisco on 24 November. An overhaul period in a drydock was a prelude to a more extensive stay in the war zone supplying the American warships that were battling the Imperial Japanese Navy. As a part of Vice-Admiral W. L. Calhoun's 7th Force, Pacific Fleet, the ammunition ship arrived at Majuro Atoll in the Marshall Islands on 2 February 1944. She replenished ships both in the Marshall Islands and at Manus Island in the Admiralty Islands. As part of the supply train of the fleet at Kossol Passage, Palau Islands, from 25 September to 2 October and at Ulithi Atoll from 4 October to 18 November 1944, she earned her first battle star. During the latter period, the Lassen rode out a severe typhoon, and she also underwent her first enemy air attack. Upon returning to the western Caroline Islands on 23 February 1945, the Lassen, along with her sister ammunition ships, worked out techniques for transferring large quantities of ammunition to warships while underway at sea. The Lassen exhibited this new ability and mobility by accompanying aircraft carrier Task Group 50.8 in raids from 13 March to 14 June 1945, while supporting the conquest of Okinawa campaign. The Lassens third battle star was earned while accompanying carrier Task Group 30.8 from 8 July to 6 August off the coasts of Japan itself. Post-war The end of the war at V-J Day found the Lassen operating out of San Pedro Bay, Leyte. On 25 October, she departed the former war zone for the United States, via Eniwetok Atoll, where she embarked 112 passengers for their transportation to the West Coast. There was little need for ammunition ships like the Lassen during the period of huge peacetime demobilization of the Navy that followed. The vessel was noted for carrying out her dangerous ammunition delivery and handling duties without any serious incidents during the War in the Pacific. She was held in port first at Port Discovery, Washington, from 20 November 1945 to 2 March 1946, and then she proceeded down the West Coast in stages, arriving at San Diego on 27 March 1946. The ship was decommissioned on 15 January 1947 and entered the Pacific Reserve Fleet. She remained a part of this reserve fleet until she was struck from the Navy list on 1 July 1961 for disposal.