continued in her familiar role as primary control ship and boat haven during "Deckhouse IV" and staged boat convoys carrying supplies up the Cua Viet River to Đông Hà. Returning to Subic Bay, Thomaston later participated in Exercise Mudpuppy II which was designed to provide training in river operations for marines. Held on Mindoro in the Philippines, "Mudpuppy II" ended three days before Christmas; and Thomaston sailed for Vietnam. 1967 She thus began the year 1967 as she had begun the previous year, in active combat operations against Viet Cong and People's Army of Vietnam units along the coastline. Participating in Deckhouse V and Deckhouse VI into March, Thomastons participation in the former operation began on 5 January 1967 when she dropped anchor off the mouth of the Cổ Chiên River. She helped to launch the thrust of "Deckhouse V", aimed at the delta lowlands of Kiến Hòa Province, South Vietnam. The combined American and Vietnamese Marine Corps landings successfully challenged Viet Cong forces in this area. Relieved at Vũng Tàu by on 6 March, Thomaston sailed for repairs at Subic Bay, en route home via Hong Kong, Okinawa, Yokosuka, and Pearl Harbor. 1968 Following an extensive overhaul at San Diego from 28 June to 18 December 1967, Thomaston departed her home port on 21 February 1968 for her regular deployment to WestPac. After joining the Amphibious Ready Group off Vietnam in the I Corps zone, Thomaston commenced operations in support of marines of the Special Landing Forces (SLF) engaged ashore in the defense of Quảng Trị Province. She spent the month of March steaming in coastwise logistics runs between Da Nang, Cam Ranh Bay and the burgeoning Army supply base at Wunder Beach. During her operations at the latter port, Thomaston demonstrated to the Army the versatility of the Landing Ship Dock by serving as an effective repair ship with a built-in drydock. Many small craft and pontoon piers serving the supply base received hull and machinery work by the crew in the ship's capacious well deck. During this deployment, Thomaston proved that the amphibious ship was a natural vehicle for inter-service cooperation. While operating off the coast of South Vietnam with the Amphibious Ready Group, Thomaston conducted two search and rescue operations. On the evening of 25 May, a CH-46 helicopter, loaded with mail, passengers, and baggage, lost power in the vicinity of and crashed. The helicopter remained