In May 1945, "Marsh" joined in the active pacification of bypassed islands in the Marianas. Broadcasting propaganda messages in Japanese and Okinawan, she sailed among the various islands of that group, including Asuncion, Anatahan, Alamagan, Sarigan, Maug, and Agrihan, taking on prisoners as they surrendered. Where the broadcasts were not successful, she escorted landing parties and provided gunfire support for the completion of their missions. By mid-July, resistance on some islands remained stiff. "Marsh", flagship of the Northern Marianas Expeditionary Force, continued to lead her small force against the holdouts in order to provide safe-ditch areas for pilots returning to Allied bases from raids on the enemy's home islands. With the securing of the islands, weather stations and aircraft beacons were set up to further aid the pilots.