After outfitting and trials off the East Coast, Monticello arrived at her home port, NS San Diego, on 27 May 1957 to join Amphibious Forces, Pacific Fleet, and immediately began shakedown training.

Such operations, involving ships of all types along with underwater demolition teams and Marines, keep the fleet at top readiness for any challenge of diplomatic crisis or war itself.

She was combat-loaded with part of a Marine reinforced battalion landing team, and was alerted four times during the Laos crisis, steaming with Paul Revere (APA-248) and four escorting destroyers in the South China Sea and the Gulf of Siam.

[1] In June, she sailed again to Christmas Island to aid in closing down the test operation, and continued to a second 7th Fleet tour of duty highlighted by a large amphibious exercise at Okinawa.

She was repossessed by the Navy on 1 July 1997 after the failure of Pegasus to dismantle the ship and was re-transferred to the United States Maritime Administration and docked in the National Defense Reserve Fleet, Suisun Bay, Benicia, California.

[2] Ex-Monticello was withdrawn from the National Defense Reserve Fleet, Suisun Bay, Benicia, California on 27 June 2010, to be towed to Hawaii for sinking, in July 2010, as part of the RIMPAC 2010 exercise.