On 28 September 1957, the ship was redesignated Advance Aviation Base Ship AVB-1. In July 1958, "Alameda County" again demonstrated her capabilities when United States Marine Corps forces landed in Lebanon, to help stabilize the volatile situation in that country. She returned to Suda Bay, on 14 July, and spent the next three months housing, feeding, rearming, and refuelling the air squadrons flying support missions for the marines in Beirut. The landing force departed Lebanon in October, and "Alameda County" resumed her drills and exercises put of Naples.