The Kimpo Regiment, in addition to maintaining security of the division left flank, was assigned the mission to “protect supporting and communication installations in that sector against airborne or ground attack.”[19] Within the division, both the artillery regiment and the motor transport battalion were to be prepared to support tactical operations of Colonel Staab’s organization. [19] KPR ComdD, Mar 52, p. 13. For defense purposes, the KPR commander divided the peninsula into three sectors. The northern one was manned by the KMC battalion, which occupied commanding terrain and organized the area for defense. The southern part was defended by the ROK Army battalion, charged specifically with protection of the Kimpo Airfield and containment of any attempted enemy attack from the north. Both forces provided for the security of supply and communication installations within their areas. The western sector, held by the amphibian tractor company, less two platoons, had the mission of screening traffic along the east bank of the Yom River, that flanked the western part of the peninsula. Providing flexibility to the defense plan was the maneuver unit, the battalion assigned from the 1st Marine Division reserve. The unit adjacent to the KPR[20] in the division line in late March was the 1st Korean Marine Corps Regiment, which had been the first division unit to deploy along JAMESTOWN. The KMC Regiment, command by Colonel Kim Dong Ha,[21] had assumed responsibility for its portion of JAMESTOWN at 0400 on 20 March with orders to organize and defend its sector. The regiment placed two battalions, the 3d and 1st, on the MLR and the 2d in the rear. Holding down the regimental right of the sector was the 1st Battalion, which had shared its eastern boundary with that of Colonel Wade’s 1st Marines until 29 March when the 5th Marines was emplaced on the MLR between the 1st KMC and 1st Marines. [20] The following month the 1st Amphibian Tractor Battalion would be added to the four regiments on line, making a total of five major units manning the 1stMarDiv front. It was inserted between the Kimpo and 1st KMC regiments. [21] Commandant, Korean Marine Corps ltr to CMC, dtd 20 Sep 66, hereafter _CKMC ltr_.