"Indiana" arrived in Seeadler Harbor, Manus Island on 26 April and Davis came back aboard his flagship two days later. That same day, she got underway in company with "Massachusetts" and four destroyers to join TF 58 for Operation Hailstone, the major attack on Truk Atoll conducted over the course of 29–30 April. On 1 May, "Indiana" took part in an attack on Pohnpei in the Senyavin Islands, shelling the island for about an hour before disengaging after having difficulty in locating suitable targets. Three days later the American fleet arrived in Majuro, where it began preparations for the invasion of several islands in the Marianas. The fleet sortied on 6 June to embark on the first stage of the campaign, the invasion of Saipan. "Indiana", "Washington", and four escorting destroyers were designated as Task Unit (TU) 58.7.3, the Western Bombardment Unit; over the course of the pre-invasion bombardment that began on 13 June and continued for two days, "Indiana" fired 584 shells from her main battery. Late in the day on 15 June, after the ground forces had gone ashore, Japanese air strikes targeted the invasion fleet. "Indiana" began evasive maneuvers to avoid the attacks, including a torpedo bomber that launched a torpedo at the ship at around 19:10 that failed to explode. Her anti-aircraft gunners shot the aircraft down, along with another bomber three minutes later. The ship was not damaged in the attacks and remained on station.