[1] After completing builder's trials at New York City and shakedown training out of Norfolk, Virginia, the amphibious transport dock ship departed the latter port on 14 August and laid a course for the west coast.

[1] During the 1964 Christmas Holidays in Subic Bay, Vancouver had the honor of welcoming aboard the USO tour group consisting of Bob Hope, Jerry Calona, Anna Maria Alberghetti, Jill St. John and Ann Sidney (Miss World 1964).

[citation needed] In February, the ship still loaded with elements of the Ninth Marine Expeditionary Brigade departed Subic Bay and took up station off Da Nang South Vietnam.

In a series of training exercises held in the Philippines, the Navy-Marine Corps teammates honed their skills for an almost instant response to any need for amphibious support or reinforcement in the Seventh Fleet's zone of operations.

Between 16 and 29 August 1966, Vancouver participated in her first combat action during Operation Deckhouse III which consisted of two landings at a point some 60 miles (100 km) east of Saigon.

The first phase, from 16 to 20 August, saw BLT 1/26 move ashore in both waterborne and airborne modes against minor opposition and later destroy a fortified Vietcong (VC)-held village.

[1] After she embarked BLT 3rd Battalion, 3rd Marines there, she returned to Vietnamese waters on 6 October and steamed with the contingency force in the area off the DMZ for the next 22 days.

After reembarking the SLF and South Vietnamese Marines on 15 January and then disembarking the latter again at Vũng Tàu the following day, she departed Vietnam to return to the Philippines.

Following a visit to Keelung Taiwan where she couldn't get into the harbor due to an impending typhoon, she returned to the Philippines early in February and conducted an amphibious exercise, "Mudpuppy III", with the Marines of BLT 1/4.

[1] At the conclusion of Operation Deckhouse VI, the amphibious transport dock ship visited Subic Bay; Hong Kong; Okinawa, and Yokosuka, Japan, before departing the latter port on 24 March to return home to San Diego.

In addition to single-ship underway training, she revisited Vancouver, British Columbia, in July to participate in a Fleet Assembly as part of the Canadian Centennial Celebration.

On 29 February, the ship steamed out of Subic Bay for the Cửa Việt River area of Vietnam where she began supporting the SLF, operating ashore since late January.

Both groups then began moving toward one another in a sweep of Elephant Valley in Thừa Thiên Province to eliminate a frequent source of hostile mortar fire on the Da Nang Air Base.

After a week without contacting the enemy, Vancouver's landing force joined shore-based units in Operation Houston IV while the ship continued in her support role.

In that operation, an all-helicopter affair, the Marines landed well inland about ten miles southwest of Hội An in east central Quảng Nam Province.

They failed to contact the enemy during the helicopter assault and, the following day, changed operational control to authorities ashore while Vancouver played her usual support role.

That phase of the task was completed in mid-April and, after a brief return to San Diego, the ship entered the Long Beach Naval Shipyard for drydocking.

Following two months of inspections and refresher training, the ship loaded vehicles and cargo at San Diego and got underway for the Western Pacific on 1 August.

[1] On 29 August, she arrived in Subic Bay and began turnover operations to relieve USS Paul Revere of duty with ARG Bravo (TG 76.5).

On 12 September, she and her group participated in Operation Defiant Stand by staging an amphibious feint about ten miles south of the actual landing beaches to draw off defenders while ARG Alfa stormed ashore.

August brought voyages to Sasebo, Japan, and Kaohsiung, Taiwan and, early in September, she returned to the Philippines for another round of practice landings at Zambales.

[1] The amphibious transport dock ship remained in San Diego through the end of 1971 for post-deployment standdown and for the usual holiday leave and upkeep period.

During April, May, and June 1973, the amphibious transport dock ship alternated tours of duty in Vietnamese waters in support of the minesweeping forces with liberty and upkeep periods in Philippine ports.

[1] Having received orders on 13 February 1975 to proceed to rendezvous with ARG Alfa (TG 76.4) Vancouver consequently cancelled a port visit to Manila and a scheduled Convoy exercise and stood out, bound for the Gulf of Thailand.

In-port maintenance for ships and embarked aircraft ensued until 1 March at which time ARG Alfa sailed to return to the Gulf, to prepare for Operation Eagle Pull, the evacuation of Cambodia.

TG 76.4 conducted training and preparations (5 March-12 April), punctuating those evolutions with swim calls on 20, 22, and 30 March to permit her crew to enjoy some relaxation.

The ships then returned to Subic Bay on 17 April, greeted upon arrival by Admiral Maurice F. Weisner, Commander in Chief, Pacific Fleet.

[1] At the end of the deployment, she departed Okinawa on 20 May 1975 and arrived back in San Diego on 6 June, and resumed west coast operations almost immediately with type training and a weapons inspection.

She made a three-day stop at Pearl Harbor at the beginning of October and put in at Kwajalein Atoll on the 10th for ARG commanding officers to conduct turnover briefings.

After a month of post deployment standdown, the ship entered the Bethlehem Steel Co. shipyard at San Pedro, Los Angeles, for her regular overhaul.