"Morrison" returned to Pearl Harbor 9 May to train for the giant amphibious leap into the Marianas. Departing Pearl 31 May via Roi, Marshalls, she arrived east of Saipan 13 June for a busy month. Her accurate gunfire supported the initial landings on Saipan the 15th and provided close fire support thereafter. With little aid the crew fought off night air attacks 17 through 19 June. Of 40 enemy planes that approached at dusk the 17th, only 15 got by the attacks of the Navy's carrier interceptor planes; and "Morrison" shot down three of those.