On 24 April 1967, a patrol from Company B, 1/9 became heavily engaged with an enemy force of unknown size north of Hill 861 and in the process prematurely triggered an elaborate North Vietnamese offensive designed to overrun Khe Sanh. What later became known as the "Hill Fights" had begun. In retrospect, it appears that the drive toward Khe Sanh was but one prong of the enemy's winter-spring offensive, the ultimate objective of which was the capture of Dong Ha, Quang Tri City, and eventually, Hue-Phu Bai.[4] That portion of the enemy plan which pertained to Khe Sanh involved the isolation of the base by artillery attacks on the Marine fire support bases in the eastern DMZ area (e.g., Camp Carroll, Con Thien, Gio Linh, etc.). These were closely coordinated with attacks by fire on the logistical and helicopter installations at Dong Ha and Phu Bai. Demolition teams cut Route 9 between Khe Sanh and Cam Lo to prevent overland reinforcement and, later, a secondary attack was launched against the camp at Lang Vei, which was manned by Vietnamese CIDG personnel and U. S. Army Special Forces advisors. Under cover of heavy fog and low overcast which shrouded Khe Sanh for several weeks, the North Vietnamese moved a regiment into the Hill 881/861 complex and constructed a maze of heavily reinforced bunkers and gun positions from which they intended to provide direct fire against the KSCB in support of their assault troops. All of these efforts were ancillary to the main thrust--a regimental-sized ground attack--from the =325C NVA Division= which would sweep in from the west and seize the airfield.[5](9) (See Map 4). The job of stopping the NVA was given to Colonel John P. Lanigan and his 3d Marines. Although he probably did not know it when he arrived at Khe Sanh, this assignment would not be unlike one which 22 years before had earned him a Silver Star on Okinawa. Both involved pushing a fanatical enemy force off a hill. [Illustration: MAP 4 K.W. White THE ENEMY PLAN] On 25 April, the lead elements of the 3d Battalion, 3d Marines, commanded by Lieutenant Colonel Gary Wilder, arrived at Khe Sanh. The following day, 2/3, commanded by Lieutenant Colonel Earl R. De Long, which was taking part in Operation BEACON STAR east of Quang Tri City was airlifted to the combat base. On the 27th, a fresh artillery battery, B/1/12, arrived and reinforced F/2/12; by the end of the day, the two units had been reorganized into an artillery group with one battery in direct support of each battalion.(10) Late in the afternoon of the 28th, the Marine infantrymen were ready to drive the enemy from the hill masses. These hills formed a near-perfect right triangle with Hill 881 North (N) at the apex and the other two at the base. Hill 861 was the closest to the combat base, some 5,000 meters northwest of the airstrip. Hill 881 South (S) was approximately 3,000 meters west of 861 and 2,000 meters south of 881N.