14 April 1966
From: Commanding Officer, 1st Battalion 4th Marines (-)(rein)
To: Commanding Officer, 4th Marines
Subj: Combat After Action Report (Operation OREGON)
Ref: (a) RegtO 3120.3
Encl: (1) Overlays of the operation
1. Type of operation. Operation OREGON was a battalion (-) (rein) search and destroy operation.
2. Inclusive dates. 200815H to 231100H March 1966.
3. Location. The area of operation was located in the Phong Dien District, Quang Tri Province, South Viet Nam. Specifically, the operation was conducted in the area bounded by (YD 480425), (YD 513473), (YD 620315) and (YD 640390).
4. Command Headquarters. Command Headquarters was Task Group Fox-Trot, Colonel T. F. FISHER, Commanding.
5. Reporting Officer. Lieutenant Colonel R. E. SULLIVAN, 1st Bn 4th Marines.
6. Task Organization
1st Battalion (-) (rein) 4th Marines
H&S Company (-) (rein)
Det 81mm Mortar Plt
Det Med Plt
Det Comm Plt
Det S-2 Sect
Vietnamese Interpreter
Det H&S Co, 2nd Bn 1st Mar
NGF Spot Team 4th Bn 12th Mar
1st Plt (-), Co A, 1st Eng Bn
Co A (rein)
Co A
Det H&S Co (-)(rein)
Det Comm Plt
Det S-2 Sect
Det Med Plt
FO Tm 81mm Mortar Plt
Vietnamese Interpreter
FAC Team
Arty FO Tm, 3rd Bn 12th Mar
Eng Sq, 1st Plt, Co A, 1st Eng Bn
Co B (rein)
Co B
Det H&S Co (-) (rein)
Det Comm Plt
Det S-2 Sect
Det Med Plt
FO Tm 81mm Mortar Plt
Vietnamese Interpreter
Arty FO Tm, 3rd Bn 12th Mar
Eng Sq, 1st Plt, Co A, 1st Eng Bn
Co E (-) (rein), 2nd Bn 1st Mar
Co E (-)
Det H&S Co, 2nd Bn 1st Mar
Det Med Plt
Det Comm Plt
Sect 81mm Mortar Plt
Vietnamese Interpreter
FAC Team
Arty FO Tm, 3rd Bn 12th Mar
7. Supporting Forces. Elements in supporting roles directly effecting the execution of this Battalion’s mission were as follows:
a. Battery C, 1st Battalion 12th Marines
b. Battery Y, 4th Battalion 12th Marines
c. Marine Helicopter Squadron 163
d. Marine Air Groups 11 & 12
e. Marine Observation Squadron 2
f. Destroyer, USS R. B. ANDERSON
g. 2216 Aviation Unit, USA
h. Marine Helicopter Squadron 164
i. Local Popular Force Units from Phong Dien District.
Marine Artillery units were employed extensively during the operation. Prep fires, on call concentrations, destruction missions, H&I missions and illumination missions were utilized on a daily basis. Heavy bombardment from Yankee Battery and the USS Anderson on D-Day and the night of D-day was bought to bear on the target area vicinity (YD 5564334).
Fire was extremely effective, and results were excellent. Helicopter support was utilized for troop lifts, reconnaissance flights, medical evacuation, and logistical resupply missions. Dependability and timeliness of support rendered by helicopter units was contingent upon their availability and weather conditions. Fixed wing observation aircraft from the 2216 Aviation Unit, USA proved invaluable on more than one occasion. The AOs were able to observe well forward of the advancing ground units, observe the fleeing enemy, and on one occasion held the enemy movement down until arrival of the Marine infantry units. This method of coordinated air/ground fix and find resulted in numerous enemies killed and captured.
8. Intelligence
a. Estimate of the enemy strength, location, disposition and situation anticipated in objective area prior to the operation.
19Mar66 – Estimated two VC Companies located Vic (GS YD 5841), believed to be elements of the 802nd Bn, 1st Provisional Regt. NV Army, and strength approx. 250 men. Also reported in same area was one local force VC Company, strength approx. 100 men. Weapons consist of 57RR, 81mm mortar and 60mm mortar, 50 cal machine guns and various individual weapons.
Fortified positions reported at (YD 571419) to (YD 581409). 57RR believed to be at this position. Three old French bunkers located (YD 519417) and individuals dug in positions at (YD 576426). The enemy has made good use of available high ground and possesses good fields of fire in all directions with ‘final protective fires’ believed to be at (YD 568410).
Conclusion – that the enemy will engage friendly troops initially with a large volume of pre-planned fire. Will attempt to withdraw after initial contact. Withdrawal will probably be to the SW, which offers the most likely avenue of egress. Use of all weapons including directional mines is a good possibility. Landmines are more than likely because of the nature in which the VC have fortified the area for defense.
b. The actual enemy strength was determined to be at least two North Vietnamese Companies supported by a heavy weapons company and rendered with a company of local force guerrillas as was indicated later by documents found in the battle area as well as information gained from local civilian sources. There was much difficulty in determining the actual size of the enemy in the initial stages of contact due to the inability to physically observe the enemy force through the heavy tree line.
The volume of fire initially was sporadic with S/A fire only. As the assault force closed on the enemy positions the volume of fire increased and a number of heavy weapons were encountered such as .50 cal, .30 cal machine guns, 60mm mortar and possibly rockets.
Reports from troops in the assault on the objective indicated the enemy made valuable use of their FPL and that it was extremely effective. Enemy fire became so intense as the assault on enemy positions continued that friendly troops could not advance without taking extremely heavy casualties. At this time arty and air strikes were effectively delivered on the enemy positions with excellent coverage of the objective area.
From all reports and indications, the enemy unit engage is believed to have been the 802nd Bn with a heavy weapons company and one local force guerilla company believed to be the K-105th.
The enemy troops appeared to be well-disciplined, well-trained and very effective marksmen. The tactics they utilized were not uncommon to good soldiering.
9. Mission. The mission as assigned by Frag Order 4-66 was as follows: Utilizing a command group and two rifle companies, move by helicopters, loading by 0815H, at LZs selected by CO 1/4, to conduct search and destroy operations in the area bounded by (YD 513473, 480425, 620315 and 640390). After the initial landing and subsequent to the cessation of the operation the mission was modified as follows: At 201400H verbal order received from TGF stated…ARVN reports enemy in NW corner of your TAOR. Sweep these areas before sweeping in original direction. At 202200H, Frag Order 5-66 ordered the Battalion to deploy forces to prevent enemy withdrawal from village vicinity (YD 555433), where the Battalion was engaged, and to sweep the village on 21 March were to land 2nd Bn 1st Mar at 0915H in vicinity (YD 518438) and sweep through GS (YD 5345). FCL line was established from (YD 530455) along the river to (YD 528447) to (YD 530439) to GL (YD 53) effective at L-hour. At 210945H verbal order from TGF notified the battalion to be prepared to continue search and destroy operations to the northwest and west in the Battalion’s operation area, with priority of effort in the village of A; Dai Phu vicinity (YD 537439). At 212047H, Frag Order 8-66 ordered that commencing at 220730H, conduct search and destroy operations to the southeast concentrating on enemy positions reported in GS (YD 5741), (YD 5841) and (YD 5840). At 230832H, verbal order from TGF ordered the Battalion to conduct detailed search and destroy operation northwest through villages to vic (YD 569420) and (YD 579434). 2nd Battalion 1st Marines will move to above position from the northwest conducting the same mission. At 231115H, verbal order received from TGF terminated Operation Oregon at 231100H.
10. Concept of the operation. The concept of the operation as originally envisioned was to land Co A initially in LZ Robin. Upon securing the zone and with the arrival of Co B, move south of the road. At such time when Co B was in position at LZ Robin, the two companies were to commence a search and destroy operation paralleling the road to the southeast terminating at the LOA vic (YD 596400). Artillery units displaced to positions affording best direct support capabilities. See operations overlay. Encl (1).
11. Execution. The initial order for Operation Oregon was received at Phu Bai at approximately 181700H March 1966. The operation itself, however, did not commence until 0800H on the 20th. Weather precluded the helicopter lift on the 19th and morning of the 20th. At 201217H, the first wave of helicopter borne Marines landed in LZ Robin. The initial lift and all subsequent lifts landed without enemy opposition. By 1255H, all elements of Company A and the Battalion Command Group were landed and had established a perimeter defense around the LZ. As remaining elements of the Battalion arrived in the LZ the perimeter began expanding in all directions. Company A at 1325H observed and immediately took under fire two VC vicinity (YD 556434). The two VC were wearing packs and dressed in Khaki uniforms. Immediately upon receiving fire the VC fled into the heavy brush and contact was lost. This incident, however, was the introduction to one of the Battalion’s fiercest and hardest fought battles during the past six months. During the battle, which raged from 1325H to 1926H, constant employment of all available supporting arms was utilized. The target area was under continuous bombardment by mortars, artillery, NGF, and air during the entire engagement. Company B, continuing to expand their perimeter met with electrically detonated mines approximately 50-75 meters forward of the tree line vicinity (YD 554314). As a result of the action Company B sustained one WIA. Reacting immediately, Company B maneuvered its reserve element to their left flank in anticipation of conducting envelopment if required. During the interim, an ARMY AO reported an undetermined number of enemies in the vicinity of (YD 524457) and instructions were received to sweep that area prior to moving as originally planned. However, before any movement could be made, Company A moving around to the northeast of the wood line to assist Company B came under heavy automatic weapons fire and 60mm mortar fire from vicinity (YD 555434). Company B continues to receive an increasing volume of fire from the northwest side of the wood line, sustaining 3 KIA’s and 4 WIA’s. Casualties resulted when elements attempting to close the objective area met with intense 50 cal. Machine gun fire. Emergency helicopter evacuation was called and received in record time. A brief evaluation of the situation at 201425H indicated that the village located in the tree line was heavily fortified with prepared positions and trench line. Bunkers and fighting holes completely covered the perimeter of the woods. An estimated one VC Company with supporting heavy weapons was initially thought to occupy the area, however as the day’s activity increased and contact became more intensified the estimate increased to two companies, possibly a Battalion, with a heavy weapons Company in support. Heavy volumes of fire continued to be exchanged by both sides by 1445H. The Battalion’s 81mm mortars were used to blanket the edge of woods facing both Company A and Company B. Artillery was utilized on positions deeper in the woods. Six HU-1E aircraft had, by this time, accurately placed their ordnance in the target area. Since forward movement by Company A was temporarily halted due to the interlocking bands of automatic weapons fire, an air strike was requested and received at 1500H. Four A-4 aircraft arrived on station and commenced bombing and strafing runs on the fortified village. 250 to 500 lb. Bombs were dropped accurately on the target area and as a result the firing diminished in volume. Upon completion of the air strike, Company A continued its maneuver forward to the objective. Almost immediately the hostile fire again commenced inflicting further casualties to the Company. Casualties for the Company now totaled four KIA’s and 24 WIA’s. Company B once again commencing to move in support of Company A received 60mm mortar fire and heavy small arms fire. This action resulted in the Company sustaining an additional 2 KIA’s and four WIA’s. Movement once again was halted while artillery and NGF from the USS Anderson fired tons of explosives on the objective area. Sixty-four rounds of 155mm were fired by 1537H and the 5” .38 cal naval guns from the destroyer fired an additional 30 rounds on the area. During the artillery bombardment the Battalion requested one rifle company to reinforce its position to permit both Companies A & B to act as assault units. Upon completion of the artillery bombardment Company A once again moved forward only to be met by intense heavy machine gun fire from well concealed and fortified bunkers. Fire was returned with small arms, automatic weapons, 3.5-inch rocket launchers and LAAWs. An additional 3 KIA and 18 WIA’s were sustained. Total enemy casualties at 1600H were recorded as 31 KIA confirmed, with an additional 40 KIA possible. Possible WIA estimated at 50. At 1624H, six 60mm mortar rounds were received from the tree line (YD 555434) by Company B, however, no casualties were sustained. Suspected mortar sites and 50-caliber machine gun positions were taken under fire by the 81mm mortar section from H&S Company. A total of 16 rounds were fired; however, surveillance was not possible. Notification was received that the requested reserve Company was being heli-lifted into position and Co E 2/1 arrived at 1700H. Additional artillery strikes were called in as were massive air strikes consisting of napalm and 20mm cannon fire. The last of the air strikes on the objective area was completed by 1915H and the Companies established night defensive positions.
All WIA’s were evacuated by helicopters by dark. Emergency resupply was requested and received during the hours of darkness, and the much-needed water, food, and ammunition was distributed. The silence of the evening was broken by the supporting artillery and NGF firing on objective area and likely avenues of approach and infiltrations with 161 H&S fires on 23 separate concentrations. NGF provided H&I illumination fire throughout the hours of darkness to prevent enemy exfiltration from the objective area. Patrols, ambushes, and listening posts were employed around the company perimeters. At 202120H, Company A observed three VC moving on the sand dunes vicinity (YD 555426). They were taken under fire with small arms M-79, and 81mm. One VC was observed to fall. No further enemy movement was detected during the night. Total Marines casualties for the day totaled 10 KIA and 47 WIA. One WIA subsequently DOW and another died as a result of a helicopter crash while in route to C-Med. The rest of the evening of the 20th and early morning hours of the 21st were uneventful. At first light on the 21st an artillery preparation was delivered on the target area prior to jump off by Company B. A total of 48 rounds of 155mm saturated the objective area after which Company B moved forward with Company A moving around to the northeast. Weather precluded use of air prep. Both companies came under heavy small arms fire and 60mm mortar fire in the amount of 12-15 rounds. 81mm and artillery fire was once again requested, the completion of which silenced the enemy’s weapons. Company B continued forward and met no further resistance. Reaching the outskirts of the village at 1010H, a six-strand barbed wire fence was found to encompass the hamlet area. Once inside the hamlet proper the Company was faced with only sporadic harassing fire. The Company found a large amount of 50 cal brass, TNT blocks and many VC packs with miscellaneous equipment, clothing, and supplies. Additionally, they found six VC bodies, four of which had been hastily buried and two only partially buried. One weapon was discovered, a Thompson submachine gun. Parts of bodies and bloodstains littered the battlefield indicating the VC had suffered heavy casualties. Ammunition littered the area including many unfused 60mm Chinese mortar rounds. All indications pointed to the fact that the VC, extremely heavily hit, had taken many casualties, and executed a rapid retreat leaving some of their dead and a great deal of equipment behind.
Company A reported finding one additional VC body at 0905H. Upon completion of the detailed search of the hamlet area the Battalion commenced its execution of the TGF Frag Order 5-66. Conducting a two Company sweep, with Company A on the left and Company B on the right, the Battalion departed the vicinity of (YD 553430) and moved to (YD 535436) then turned north and swept to the FCL vicinity of (YD 535448). No enemy contact was made during the tactical move north and the Battalion established its night defensive position in the vicinity of (YD 539448) at 1620H. Saturation patrols, ambushes and listening posts were planned and executed during the hours of darkness, however, no enemy contact was made. At 212047H, the Battalion received TGF Frag Order 8-66 for the following day. This order in essence executed the original order as stated in TGF Frag Order 4-66. At 220730H, the Battalion moved from its night position to the highway, vicinity (YD 536436). Reaching the roadway, Companies A & B deployed to form a 600-meter skirmish line on either side of the road and commenced the Battalion sweep southeast. Company E followed in trace behind the battalion command group. By 0945H, Company B had approached the hamlet in vicinity (YD 55434). The forward movement was halted while artillery prep was called down on the one-time VC strong hold. This precautionary measure was felt necessary in case some VC had infiltrated back into the area. Upon completion of the prep fires the Company moved into the tree lined village once again. The second sweep uncovered a Chinese K-50 and two VC bodies vicinity (YD 557433). Upon completion of the sweep at 1100H, the skirmish line proceeded southeast once again. Close air observation was conducted during the sweep by an AO from the 2216 Aviation Unit, USA. At approximately 1230H the AO observed six to 10 VC fleeing to the southeast about 500 meters ahead of the advancing Marine units. Closing rapidly, Company B engaged the VC at vicinity (YD 583424). A brief but intensive exchange of fire resulted in 3 VC KIA’s and 5 VC WIA’s. Two of the VC voluntarily surrendered when wounded. Two VC packs with miscellaneous supplies, food, and clothing were captured. At 1245H the AO reported two additional VC were hiding by a paddy dike, vicinity (YD 578426). A quick change in direction and aggressive searching resulted in two additional VC KIA. None of the VC were found with weapons, only Chinese and M-26 hand grenades. Continuing their methodical and aggressive searching, the Company received 8-10 rounds small arms fire from vicinity (YD 585424). The company immediately returned fire with 40-60 S/A and numerous M-79 rounds. This action resulted in four additional VC WIA’s captured at 1340H. The total VC casualties were 5 KIA and 9 WIA, and no Marine casualties. While awaiting helo evac one of the seriously wounded VC died. The advance continued toward PF Six (YD 590407) with no further contact. During the sweep a total of 53 VCS were apprehended 31 of which were detained by the District Chief and sent back to District Headquarters for further interrogation. The remaining 22 were cleared and sent home. The Battalion CP set in for the night at vic (YD 590407) and established saturation patrols, ambushes and listening posts. The only enemy contact made during the evening was two incoming grenades received by Company B at (YD 596402). No casualties were inflicted. At 230832H, the Battalion received orders to resweep the same area back to vicinity (YD 536437). By 0900H, the Battalion had commenced its sweep back with Company B on the north and Company A south of the road. While enroute and at 231100H, orders were received that Operation Oregon had been terminated as of that time.
12. Results. Four-day operation netted the following casualties and equipment losses:
a. USMC, KIA – 10, WIA – 45, DOW – 1
b. Viet Cong, KIA – 48 confirmed, KIA – 40 possible, WIA – 8 confirmed (captured), WIA – 50 possible, VCC – 2, VCS – 31
No Marine Equipment Lost
Viet Cong Equipment Losses
1 Thompson SMG 1 clip .30 cal ammo
1 AK-50 3 Chinese Stick grenades
1 Magazine F1 AK-50 .50 cal cartridge belt
500 AK-50 rounds 50 rounds .30 cal M-1
1 .38 cal pistol holster 21 blasting caps
150 Rounds cal .45 8 lbs. TNT
1 Old type claymore mine 7 grenade pouches
18 miscellaneous packs miscellaneous medical
14 Cartridge belts supplies
7 Ponchos miscellaneous VC
4 Raincoats plastic documents
4 Canteens 1 82mm mortar round
1 81mm mortar round 3 German rocket rounds
2 Entrenching tools 3 green hammocks
13. Administrative matters.
a. Logistics. The initial mission as planned was scheduled to be completed within 48 hours. Accordingly, only minimum personal equipment, water and rations were carried to the field. Initial ammunition loads included one unit of fire per weapon. As the situation increased in tempo, emergency resupply was necessary. Resupply of ammo, water, and rations was accomplished during the hours of darkness and without unnecessary hazards to either the helicopters or ground personnel. Nighttime resupply was again affected on the 21st, once again it progressed smoothly. LZs were marked with illumination grenades followed by close-in direction wands for final approaches. On the 22 and 23 March, resupply was conducted during day light hours. Before the operation terminated all units were resupplied on an ‘as required’ basis with socks, utilities, oil, and boots. In general, resupply was outstanding.
b. Casualty evacuation. All casualties were evacuated efficiently and rapidly, with minimum time delay. Average processing time per patient was 12 minutes. All casualties were air evacuated within 30 minutes after arrival at the BAS.
c. Maintenance. All maintenance within 1st and 2nd echelon capability was conducted. Equipment requiring higher echelon maintenance viz., radios, was evacuated with replacements returning within a few hours, normally on returning supply or med-evac helicopters.
d. Communications. No adverse problems. Some difficulty arose with Command Net communications utilizing the PRC-47. This was primarily due to the area involved, not the equipment. PRC-25s worked and held up excellently.
14. Special Techniques. Division trained snipers were employed during the operation. The snipers accounted for eight of the 31 confirmed kills on the 20th. The VC were observed fleeing at distances up to 600 meters from the front lines. Effective accurate shooting brought the enemy hostile activity to an end.
15. Commanders Analysis. No unusual problems were encountered. However, there are several aspects of the operation worth noting.
a. During the initial contact on the 20, the Battalion employed all four available supporting arms in planned sequence, viz., 81mm mortars, artillery, NGF and air. The coordination and employment of these weapons proved most satisfactory.
b. Artillery support from ‘Y’ Battery 4/12 was outstanding. This composite unit provided excellent, accurate and timely artillery support to the ground units.
c. Dispersion once again plays a key role in offensive tactics. Many more casualties would have been inflicted on the 20th had the Marines not been well spread out. Distances of 15 and 20 meters, when moving through open area, are mandatory. The tendency still exists to bunch up and close up when moving forward, especially when contact is first made. Only constant supervision at all levels will preclude this. In this light a strong point with maximum fire capability is a necessity. The point, when operating in rice paddies and vast open areas must be at times well forward of the sweeping elements. In this regard connecting elements may be required if paddy areas are pock marked with pine or bamboo groves which impede continuous unobstructed observation. Additionally, these groves are excellent ambush sites and afford the insurgent maximum grazing fire at advancing Marine units. The point must be aggressive, alert and determined in their actions in these and other prospective ambush sites if grave damage is to be prevented to the main body.
d. AO support during sweep operations is invaluable. A typical VC tactic is to direct harassing fire at approaching Marines, then exfiltrate through pre reconnoitered routes and evade the searching elements. The presence of an AO precludes and hinders the exfiltration of the enemy, for many movements can readily be seen from the air, and subsequently the VC can be observed until the advancing elements can be guided to their position. This air/ground team proved itself on the 22nd when the AO directed elements of Company B to the VC hideouts and permitted the Marines to pursue and engage the fleeing VC. This coordinated pursuit netted 5 VC killed and 8 VC sounded and captured. It is recommended that whenever possible an AO should be on station to assist ground elements in their sweep.
16. Recommendations.
a. The weight and cube of potable water makes it a particular resupply problem. One method of alleviating the requirement of water recovery can be the development and use of strong polyethylene bags to hold water. The bags would require rigid outboard support, such as a strong durable corrugated cardboard box. The plastic bag could be inserted, and air delivered as required. When the contents are emptied the container would be destroyed.
b. The basics of tactics and techniques of conventional warfare must be reemphasized at every level of training. Once contact was made, all the components of a conventional situation existed.