The main US Army operation took place Process_start in an area about north of Bien Hoa , where the US 1st Battalion , 503rd Infantry Regiment ( 1/503 ) , 173rd Airborne Brigade conducted Action a helicopter assault on an LZ northwest of the Dong Nai River and Song Be River .

The 1st Battalion , Royal Australian Regiment ( 1RAR ) was deployed Arranging south of the Dong Nai .