After completing her initial missions at Pusan and between that port and Japan, "Arikara" moved to other areas of the Korean peninsula. On 5 September, she departed Yokosuka with Task Unit (TU) 90.04.3, the Pontoon Movement Unit, on her way to Inchon on the western coast of Korea. The tug supported the amphibious assault at Inchon from mid-September to mid-October, before heading, on the 16th of the latter month, for Wonsan on the northeastern coast of Korea. The 20 October amphibious assault on Wonsan, mooted by the arrival of rapidly advancing Republic of Korea (ROK) ground forces, was transformed into an enormous reinforcement and logistical support operation. "Arikara" spent about a month at Wonsan helping to clear the harbor and to increase its efficiency.