 In September 1969 as part of Operation Keystone Cardinal the 3rd Marine Division began its withdrawal from Vietnam and by early October the Marines had handed over control of their tactical area of operations (including the Gio Linh base) to the 1st Brigade, 5th Infantry Division and the ARVN 1st Division.In 1970 the M55 Self Propelled Howitzer of the Marines 5th 175mm Gun Battery remained at Gio Linh under the command of the Army's 108th Artillery Group.A small number of Marines remained at Đông Hà as part of the ANGLICO unit supporting the ARVN 1st Division.