In late May, intelligence gained during Operation Cameron Falls and from sensor and reconnaissance reports indicated that the People's Army of Vietnam (PAVN) 24th Regiment of the 304th Division had infiltrated Quảng Trị Province near the Khe Sanh plateau.

Task Force Hotel which was responsible for this area of Quảng Trị Province ordered the formation of Joint Task Force Guadalcanal, comprising 1st Battalion, 9th Marines, and Task Force Mustang, comprising Companies B and C, 1st Battalion, 61st Infantry Regiment (Mechanized) and Company B 1st Battalion, 77th Armored Regiment of the 1st Brigade, 5th Infantry Division (Mechanized) operating with the ARVN 2nd Regiment to sweep the area.

[1][2]: 250 At 03:35 on 18 June over 100 soldiers from the PAVN 24th Regiment attacked Company B 1/61st Infantry's night defensive position east of Lang Vei penetrating the perimeter.

Later that day a reconnaissance patrol from Company C 1/9 Marines patrolling 3 km southeast of Khe Sanh was ambushed by entrenched PAVN with three Marines killed by machine gun fire, the ambushed platoon was recovered by the rest of Company C and they overran the PAVN position.

[1]: 72 This article incorporates public domain material from websites or documents of the United States Marine Corps.