Arriving Pearl Harbor 29 November, the ship again turned to amphibious training, in preparation for the epochal Iwo Jima landings, one of the most important steps in the Navy's island campaign that drove relentlessly toward Japan.

In addition to her regular duties, Highlands received over 150 survivors of Bismarck Sea 22 February, as well as casualties from the hard-pressed Marine units ashore.

The transport remained at Kerama Retto until 11 April, when she took part in the early morning assault on Tsugen Jima, a small but key island controlling the approaches to the large bay on Okinawa's east side.

As Marines gained control of the island, Highlands took casualties on board, and moved directly off Hagushi beaches 12 April to disembark reserve troops.

.During the 3 days that followed antiaircraft fire and smoke screens helped protect the transport from almost continuous air attack, and after completing her mission Highlands sailed for Saipan 16 April.

Highlands and other transports of her group entered Tokyo Bay the day of the formal ceremony, 2 September, and landed units of the 1st Cavalry Division on Japanese soil.

Highlands arrived Hampton Roads 26 January, decommissioned 14 February and was placed in the United States Maritime Commission's National Defense Reserve Fleet, James River, Virginia.