[305] HqBn SAR, 10–11; Smith, Notes, 513–514; CG 1stMarDiv msg to Subordinate Units, 2200 3 Nov 50; MajGen E. W. Snedeker Comments, 4 May 56.
A perimeter defense, consisting of two outposts and eight machine-gun positions, was set up to command all likely approaches to the new CP. Defensive wiring and trip flares were installed, with the gun positions and outposts being connected by telephone.
During these proceedings everyone was blissfully unaware of the existence of 250 tons of NKPA high explosive, stored only 600 yards from the CP in three connecting caves. Undiscovered for a week, this enemy cache was believed capable of demolishing the command post. A 16-man security detachment was placed on guard until the explosive could be removed and detonated.[306]
[306] HqBn SAR, 10–11; Smith, Notes, 513–514. Some explosive, too unstable to be moved, was left in the caves. Gen O. P. Smith ltr, 15 Apr 56.
Attacks on Wonsan-Hungnam MSR
Protection of the Wonsan-Hungnam MSR took on added importance as the 1st Marine Division speeded up its move to the north. This responsibility, it may be recalled, was shared by Division and Corps on 3 November in accordance with a decision by General Almond. The 1st Marines and elements of the 1st Tank Battalion maintained security from Wonsan 15 miles northward to Munchon, while the 1st Battalion of the 5th Marines was responsible from Hamhung southward to Chigyong. This left the 54-mile stretch between Chigyong and Munchon without any protection except the patrols of the Korean CIC agents and the Special Operations Company, USA, both under Corps control.
On 4 November this company reported that large numbers of North Koreans were moving into the area to the west. That same afternoon Corps notified Division that a group of mounted guerrillas had fired on railway police in the yards at Kowon, 15 miles north of Munchon.[307]
[307] Smith, Notes, 472–473; G-3 SAR, 21. The previous day an A/Tks patrol had killed an estimated 150 NKs in a short fire-fight west of Munchon. 1stTkBn, SAR, 12.
On 6 November, immediately after landing at Wonsan, the 65th RCT of the 3d Infantry Division (less one battalion, placed temporarily under 1st Marine Division control for the Majon-ni operation) was ordered by Corps to relieve elements of the 96th Field Artillery Battalion, USA, which had been recently sent to Yonghung. The Army RCT was assigned a mission of protecting the Yonghung-Kowon area and patrolling to the west (see map on Page 122).[308]
[308] CG X Corps msg X12075, 5 Nov 50; Dolcater, 3d Infantry Division in Korea, 69; Smith, Notes, 473.