In early May 1969, U.S. reconnaissance detected that two People's Army of Vietnam (PAVN) Regiments, the 27th and 36th, were infiltrating through the Vietnamese Demilitarized Zone (DMZ) into the central section of Quảng Trị Province.

[3]: 1  On 20 May, an estimated force of 20 PAVN attacked Company C's night defensive position losing 15 killed for the loss of three Marine dead and eight wounded.

[3]: 5–78  3/3 Marines swept south from Gio Linh towards Con Thien killing 20 PAVN in two separate engagements before midday on 17 June.

[2]: 74–5  At 14:00, an estimated PAVN company attacked the 3/3 Marines' command position but were forced back with the loss of 37 dead and three captured.

[4] This article incorporates public domain material from websites or documents of the United States Marine Corps.