A county in northwestern Minnesota.
Mahnomen County (LST‑912) was laid down as LST‑912 by Bethlehem‑Hingham Shipyard, Inc., Hingham, Mass., 5 February 1944; launched 22 April 1944; sponsored by Mrs. Hazel B. Leppe; and commissioned 21 May 1944, Lt. Lloyd R. White in command.
Assigned to the 7th Amphibious Fleet, LST‑912 sailed in convoy 25 June for the Admiralty Islands, via Bora Bora, Societies, and Noumea, New Caledonia, arriving Seeadler Harbor, Manus, 23 August to unload her cargo of one LCT and sections of another. She steamed for New Guinea 8 September, arriving Humboldt Bay, Hollandia, 2 days later for exercises until 22 September, when she departed for Morotai Island. Following her arrival the 27th, LST‑912s guns helped drive off an enemy bomber which raided the harbor area.
On 29 September LST‑912 proceeded to Soemoe Island to embark men and equipment of the 113th Naval Construction Battalion for transfer to Hollandia. Despite harassment of her task unit by three enemy aircraft the next day, she reached Hollandia 5 October. Five days later she moved on to Pie Beach to take on Army troops and equipment for the invasion of the Philippines. The landing ship joined a task group off Hollandia 16 October, and, entering Leyte Gulf on the 22d, ran through the surf to land her soldiers at White Beach. LST‑912 then served as an emergency evacuation hospital, receiving six Army casualties the 23d, before retiring to HolIandia 6 days later.
On 3 November the tank landing ship sailed to Wake Island to embark troops of the 303d Airdrome Squadron for passage to Leyte. Just as she finished debarking her troops at Yellow Beach, a "Zero" roared in and began strafing the shore. Her guns quickly brought the plane down and LST‑912 headed for New Guinea arriving Hollandia 6 days later.
After loading equipment and personnel of the 79th Army Engineer Construction Battalion 23 December, LST‑912 sortied with a task group for Lingayen Gulf the 26th, via Sansapor, New Guinea. On the evening of 7 January 1945 a Japanese destroyer closing the formation in the Surigao Straits was intercepted and sunk. At 0255 Japanese planes attacked the task group and 3 hours later a "Val" careened into the LST killing four men, the vessel-s only wartime casualties.
Arriving off Lingayen Gulf 9 January, LST‑912 discharged her cargo and men on White Beach the next day. The next 2 days were spent under constant enemy fire until she steamed back to Leyte Gulf, arriving the 17th to repeat the cycle.
Back in Leyte Gulf 5 February, LST‑912 took on units of the 13th AAF on the 17th; landed the group at Mindoro Island, Philippines, the 22d; embarked parts of an Army Engineer Battalion of the 30th Quartermaster Company for the invasion of Palawan Island 28 February; and departed Mindoro the 26th. The ship received four Army casualties at Puerto Princesa, Palawan, for passage 2 March to Mindoro. She continued transport trips between Mindoro and Palawan until the 12th when she departed for Manila with the 866th Engineer Aviation Battalion on board, arriving the following day.
Her next amphibious operation was Legaspi, Philippines, she took LCM‑468 in tow 28 March at Subic Bay, and arrived off Lemery, Luzon, the 30th to embark the 158th Regimental Combat Team for the invasion of Legaspi 1 April, the last amphibious operation in the Philippines. LST‑912 moved troop units in Legaspi through 8 April; then steamed for Mindoro, arriving Marguin Bay 11 April.
After the landing ship debarked equipment at Zamboanga 19 April, she departed for Pollac Harbor 21 April to disembark supply troops 7 days later for the continuing effort to liberate the Philippines. On the 29th LST‑912 moved on to the next naval objective, the Borneo landings.
Following her arrival at Biak Island 7 May, units of an RAAF airfield construction squadron came onboard for an assault at Brunei Bay, Borneo, 10 June. While remaining off the beaches receiving casualties, she received orders 18 July to transport Australian service personnel to the Kuala Belait area.
She returned to Leyte Gulf on the 26th and was there when the armistice was declared 15 August. The LST was involved in occupation duties until December, visiting Morotai and Luzon, Philippines; Sendai and Yokosuka, Japan; and Guam before arriving at Iwo Jima 20 December to load Army supplies for the United States.
LST‑912 reached San Diego 21 January 1946. Reassigned to the Atlantic Fleet, she sailed via the Panama Canal for the Gulf of Mexico on the 30th, arriving New Orleans 20 February to continue in commission with the 16th Reserve Fleet. On 30 October 1946 she was returned to active status and departed the Washington Navy Yard for 2 years of duty with the Amphibious Force at Little Creek, Va.
Assigned to the 6th Fleet in July 1948, LST‑912 departed Morehead City, N.C., 5 September for Europe, arriving Tangiers the 23d. She cruised the Mediterranean into 1949, visiting Sicily; Tripoli, Libya; Bizerte, Tunisia; Malta; and Marseilles, France, before returning to Morehead City 6 February 1949. From 8 to 16 March the landing ship participated in the annual Caribbean amphibious exercises of operation "Springboard." LST‑912 continued to conduct amphibious training out of Little Creek with occasional trips to the West Indies until 1955. From 28 July to 13 August 1952 she was anchored off Thule Greenland, resupplying an American airfield as part of operation "Bluejay."
LST‑912 was placed in reserve in January 1955. On 1 July she was renamed Mahnomen County. On 25 August she decommissioned and entered the Atlantic Reserve Fleet at Green Cove Springs, Fla.
Mahnomen County recommissioned at Philadelphia, Pa., 27 March 1963, Lt. (jg.) John H. Withers in command. Assigned to Reserve LST Squadron 2, she served for the next 3 years in the 5th Naval District, operating along the Atlantic coast from New York to the Bahamas.
On 21 December 1965 Mahnomen County was again placed in the active fleet; and on 27 January 1966 departed Little Creek for Charleston, S.C., arriving the 29th to embark Army supplies. The next day she sailed for Southeast Asia with Pulaski County (LST‑1088) and New London County (LST‑1066), stopping at Pearl Harbor 4 March to 21 April before continuing on to Vietnam via Okinawa, arriving Vung Tau 27 May. She operated as a military transport and supply ship between Sasebo, Japan; Subic Bay, Philippine Islands; Kaohsiung, Taiwan; and Phan Rang, Vietnam, through the next 7 months, supporting the effort to curb aggression in South Vietnam.
On 3 December Mahnomen County departed Kaohsiung for Vietnam, docking at Chulai on the 18th. On 30 December she was driven ashore by the 18‑foot surf and high wind of a typhoon. Attempts to refloat the wrecked LST during January 1967 were unsuccessful. Mahnomen County was struck from the Navy List 31 January 1967; and, stripped of any salvageable materials, her hull was demolished by the Navy Support Detachment at Chulai.