RCT-31 primarily consisted of infantry, artillery, and tank units from the 7th Infantry Division including the 31st Infantry Regiment, 57th Field Artillery Battalion, 13th Engineer Combat Battalion, 73rd Heavy Tank Battalion, and the 15th Antiaircraft Automatic Weapons Battalion. It was also augmented by KATUSA (also known as ROKs).[1]
The units of RCT-31 positioned at the Chosin Reservoir from 27 Nov–2 Dec 1950 consisted of 3rd Battalion/31st Infantry, 1st Battalion/32nd Infantry Regiment, A and B Batteries/57th Field Artillery Battalion, D Battery/15th Anti-aircraft Automatic Weapons Battalion, and 750 KATUSA soldiers
