Following shakedown in Guantanamo Bay, Cuba, LST-1162 operated out of the United States Atlantic Fleet's Naval Amphibious Base Little Creek, Virginia Beach, Virginia, for the remainder of 1953, conducting local operations out of Little Creek and off the coast of Florida. In 1954, LST-1162 participated in Atlantic Fleet amphibious maneuvers "NprAmEx" and "LantFlex" and conducted operations with the Operational Development Force out of Key West, Florida, testing antisubmarine warfare gear. Later during 1954, LST-1162 visited Havana, Cuba, with embarked naval reservists. During March 1955, LST-1162 operated off Bloodsworth Island, conducting gunfire tests and serving as range safety vessel at the Navy's gunnery practice areas there. On 1 July 1955, USS LST-1162 was named USS Wahkiakum County. For the next five years, Wahkiakum County pursued a regular schedule of operations off the United States East Coast and into the Caribbean and Gulf of Mexico. She was deployed in the Mediterranean Sea in 1958 and 1959, both from January through June. Operating with the Atlantic Fleet's amphibious force, she served alternatively as a helicopter carrier -— a harbinger of the roles which other ships of her type would perform during the Vietnam War; a shore bombardment safety vessel; an afloat gunnery training ship; and a transport for Navy construction battalions and their equipment.
Atlantic, Caribbean, and Mediterranean operations, 1960-1965
At the end of this period, she deployed to the Mediterranean Sea and operated with the 6th Fleet from May to December 1960. She carried cargo and troops and participated in amphibious exercises with naval units of North Atlantic Treaty Organization countries in the Mediterranean. Wahkiakum County underwent a major at Newport News, Virginia, in 1961, before she resumed active operations with a three-month Caribbean deployment. Transferred to Amphibious Squadron 12 on 1 July 1961, Wahkiakum County participated in several amphibious landing exercises and contingency operations over the remainder of the year. During July and September 1961, she transported United States Naval Academymidshipmen from Annapolis, Maryland, to Little Creek, Virginia, for annual summer training and began a three-month Caribbean deployment in September 1961. During the Cuban Missile Crisis in the autumn of 1962, Wahkiakum County embarked the 2nd Battalion, 8th Marine Regiment, and operated in support of the blockade of Cuba from 24 October 1962 to 7 December 1962. She deployed to the Mediterranean in the spring of 1963, operating with the 6th Fleet Amphibious Task Force, and again to the Caribbean during the spring of 1964.
On 24 April 1965, supporters of the ousted Dominican Republic President Juan Bosch launched a coup d'etat in Santo Domingo, which soon degenerated into a civil war, with loyalists battling a rebel group backed by armed civilians. As the fighting threatened Americans there, the United States sent U.S. Marines to protect and evacuate Americans. When it appeared that the revolt had been taken over by Fidel Castro's Cubans, the United States intervened with more men —- paratroops of the 82nd Airborne Division and Marines. During the period from 9 May 1965 to 17 May 1965, Wahkiakum County operated in support of this evacuation and intervention operation.
Mediterranean and Caribbean operations, 1965-1970
For the remainder of the 1960s and into 1970, Wahkiakum County operated on regular deployments to the Caribbean and Mediterranean.