As a three squadron group, the 498th Group moved to the Mariana Islands in the North Pacific in September 1944, being assigned to the 73d Bombardment Wing, XXI Bomber Command, at Isely Field, Saipan. Upon arrival the group's personnel were engaged in Quonset hut construction. By mid-October most personnel were able to move into the huts from the initial tents in which they were accommodated on arrival. The group began operations with its first combat missions against Iwo Jima and the Truk Islands. Took part in the first attack (24 November 1944) on Japan by AAF planes based in the Marianas. Conducted numerous attacks against industrial targets in Japan, flying in daylight and at high altitude to carry out these missions.