Once the Da Nang landing was completed, "Vernon County" moved south and took part in one of the largest amphibious undertakings since the 1950 Inchon landings in South Korea when she participated in the 6 May landings at Chu Lai, South Vietnam. In that operation, three U.S. Marine Corps battalion landing teams and a U.S. Navy mobile construction battalion went ashore to initiate construction of an airfield.