 Based on prisoner interrogations, American intelligence believed that the PAVN 6th Battalion, 12th Regiment was operating in the Cay Giep Mountains east of Bong Son.General Kinnard wanted to encircle and annihilate it.The ARVN 22nd Division surrounded the target area, deploying along the Lai Giang to the north, Highway 1 to the west, and the Tra O Marsh in the south, while the division's junk
fleet patrolled the coast to prevent escape by sea.