In early June, ARVN intelligence sources indicated that the 806th and 812th Regiments of the People's Army of Vietnam (PAVN)
6th Division were operating in the Quảng Điền District of Thừa Thiên Province. On 23 June an ARVN unit operating in Quảng Điền was mauled by a large PAVN unit. 4th Marine Regiment commander Col. Donald W. Sherman developed a combined operation with the ARVN 1st Division that called for the 2nd Battalion, 4th Marines to be landed on the O Lau River, while the 2nd Battalion, 1st Marines were landed 6km southeast to establish blocking positions, the 4th Marines command group and 3rd Battalion, 12th Marines would occupy blocking positions near Phong Điền to the southwest, while the ARVN 1st Division (in Operation Lam Son 284) would occupy blocking positions to the northeast across the mouth of the O Lau River. Once the units were in place, the 2/4 Marines would advance southeast along Route 597 towards the 2/1 Marines.