16 November 1966
From: Commanding Officer, 1st Battalion 4th Marines
To: Commanding Officer, 4th Marines
Subj: Combat Operations After Action Report (Operation Prairie).
Ref: (a) RegtO 3120.3B
(b) Maps: AMS Series L701, 1:50,000
Sheet 6361 I Cam Lo
Sheet 6361 II Thon Doc Kinh
Sheet 6361 III Ap Adua
Sheet 6461 IV Kuong Kim
Sheet 6461 III Ap Quam
Encl: (1) Overlays of the Operation
1. Type of Operation. Operation ‘Prairie’, Search and Destroy Operation.
2. Dates of Operation. 161630H August to 010800H November 1966 (Chop 3rd Mar Div)
3. Location. Quan Cam Lo District, Quan Huong Hoa District, Quang Tri Province, Republic of South Viet Nam
4. Command Headquarters:
1st Battalion 4th Marines LtCol Jack Westerman
Company A Lt W.L. Hartley (16-23 Aug)
Lt G.T. Galvin (24 Aug-10 Oct)
Capt R.F. Corcoran (11 Oct – 1 Nov)
Company B Capt R. Frederickson (16 Aug – 1 Oct)
Capt J.A. May Jr. (2 Oct – 1 Nov)
Company D Lt. D.K. McMahon (16 Aug – 24 Sept)
Lt J.F. Juul (25 Sept – 15 Oct)
Capt R.D. Kelley (16 Oct –1 Nov)
H&S Company Capt J.A. May Jr. (16 Aug – 1 Oct)
Capt C.F. Divelbiss (2 Oct – 11 Oct)
Capt E.H. Boyd (12-22 Oct)
Capt C.F. Divelbiss (23 Oct – 1 Nov)
5. Task Organization
1st Bn (-) (rein) 4th Marines (rein) LtCol Westerman
H&S Co (-)
Company A
Company B
Company D
3rd Sqd, 1st Plt, Co B, 3rd Eng Bn
6. Supporting Forces:
a. 3rd Battalion 12th Marines; 2nd Battalion 12th Marines; M Battery 4th Battalion 12th Marines supported this Battalion at various times during the operation. Artillery was employed extensively, particularly during September. During September prep fires, on-call concentrations, destruction missions, H&I's and Illumination were used almost daily. Fire was extremely effective with excellent results.
b. Air was provided by the 1st Marines Aircraft Wing. Helicopter support was utilized for troop lifts, reconnaissance flights, Med-Evacuations, and logistical resupply missions. Dependability and timeliness of support rendered by helicopter units was above average. Fixed wing observation aircraft proved invaluable on many occasions throughout September. The AO’s were able to observe well forward of advancing ground units, observe the enemy, direct friendly movements and aid in controlling Close Air Support. Close Air Support was utilized extensively during September. On-call CAS reaction time averaged approximately 20 minutes. The timeliness and effectiveness of CAS aircraft was outstanding. Preplanned and immediate request were called utilizing the 4th Marines TACP net. During darkness TPQ, 10 strikes were planned and called on likely avenues of approach. The USAF C-47 Flare ships provided support on 7 nights during September with outstanding effectiveness.
c. 3rd Squad, 1st Plat, Co B, 3rd Engr Bn was attached to this Battalion from 2-23 Oct but their services were not used.
d. In late August Company C of the 3rd Tank Bn provided direct support for a one-day tank-infantry reconnaissance in force operation between Cam Lo and Con Thien outpost. In September platoons from Companies A and C of the 3rd Tk Bn provided direct fire support in the Thon Son Lam operating area grid squares XD 9756 and YD 9757 against enemy fighting holes, machine gun and recoilless rifle positions with excellent results. During October tanks added to our defensive posture while manning defensive positions at Dong Ha Combat Base, the mouth of the Cua Viet River (YD 346698) and the Cam Lo Bridge site (YD 148604).
7. Intelligence
a. General. Prior to entering the area of operations it was estimated that elements of the 324th NVA Division were operating in the Dong Ha/Cam Lo area. In addition local force VC elements were operating in the area of operations. During the operation it was reported that elements of the 341st NVA Division were operating north of the Cam Lo/Dong Ha area.
b. Enemy Strength and Composition.
(1) 324th NVA Division
(a) Subordinate Units
90th Regiment – 7th, 8th and 9th Battalions
812th Regiment – 4th, 5th, and 6th Battalions
803rd Regiment – 1st Battalion (600 men)
3rd Battalion (550)
(2) 341st NVA Division (elements of)
c. Location. The 1st Battalion of the 803rd Regiment was reported to be operating in the vicinity of XD 9662. The 3rd Battalion of the 803rd Regiment was reported to be operating in the vicinity of YD 1051. Other enemy units were operating in or near the DMZ with subordinate, units infiltrating into the area of operations.
During the operation two Main Force Companies were encountered in the Cam Lo area. One of the companies was believed to be the Cam Lo District Local Force Company with Main Force elements. Identification of the other was undetermined.
Also a NVA unit of approximate Regimental size was engaged in the vicinity of XD 9660 during the operation. The main enemy force was believed to be operating north of the general area. No unit identifications were made.
d. Weather and Terrain.
(1) Cover and Concealment. There was cover and concealment for both friendly and enemy units in the area of operations. The heavy canopy and dense jungle provided excellent cover and concealment for the enemy. In many instances the canopy was higher than a man and thus offered the enemy concealment from both the air and ground observation.
(2) Obstacles. No man-made obstacles were encountered during this operation. However, vehicle traffic was usually restricted to the roads. The enemy’s attempts to slow or stop vehicular traffic by destroying the numerous bridges along Route #9 from Dong Ha to Thon Son Lam turned into a futile effort on their part. The bridges were either repaired or by-passed.
(3) Critical Terrain Features. The Song Cam Lo/Song Hieu Giang River runs from west to east. Two key terrain features were encountered during the operation. The first was the Thon Khi Tri ‘The Rock Pile’, Grid Square (XD 9759) which rose 220 meters from the valley floor. The second was a large rock formation ‘The Razor Back’, Grid Squares (XD 9664-XD 9558) 4,000 meters in length, with heavy vegetation and innumerable caves.
(4) Observation and Avenues of Approach. During the operations the TPS-21 was utilized in conjunction with an OP on top of ‘The Rock Pile’. The radar covered all suspected avenues of approach on the SW side of ‘The Rock Pile’, and the western half of the Song Thinh Hin River. Observation was excellent from this position and was only hindered by an early morning fog, which burnt off shortly after sunrise.
(5) Weather High Low
(a) Temperature 96 68
(b) Humidity 81% 67%
(c) Visibility generally good, 12-15 miles.
(d) Winds generally calm, 4-8 knots
(e) Rain fall during the operation was moderate to heavy
during the latter part.
8. Missions. During the period 16 August – 1 November the Battalion participated in Operation Prairie in the Dong Ha – Cam Lo area. Missions assigned were as follows:
a. The Battalion responsibility for defense of the airfield at Dong Ha and the Artillery position at Cam Lo, 16 August – 29 August.
b. On 23 August the Battalion conducted a Tank/Infantry Search and Destroy Operation (one company reinforced) to Con Thien (YD 117701) from Cam Lo.
c. During the period 30 August - 5 September the Battalion conducted a reconnaissance in force in an area north of Highway #9 and west of Cam Lo to Thon Son Lam.
d. Period 6 September – 7 September.
(1) Defended Dong Ha Combat Base and coordinated defensive efforts of all U.S. Forces within perimeter.
(2) Provided one reinforced rifle company to be used as a reaction force.
e. 8 Sept – 1 Oct conducted operations to prevent enemy movement into or through Thon Son Lam area (vicinity XD 9756).
f. 1-31 Oct
(1) Defended Dong Ha Combat Base and coordinated defensive efforts of all U.S. Forces within perimeter.
(2) Deployed one Company to provide security for a Naval Support Activity at XD 340698 from 10 October until 31 Oct.
(3) From 1-6 Oct, provided one company as security for an artillery position located at Con Thien (Grid Square YD 1170).
(4) 15-16 Oct and again from 19-31 Oct provided elements of one company as security for a bridge located at YD 148604, near Cam Lo.
9. Concept of Operations:
The Battalion Concept of Operation for Operation Prairie was to conduct reconnaissance, both small unit and in force, in order to locate and destroy enemy forces in the area. A defensive position was established in the Thon Son Lam area (XD 9756) from 8 Sept – 1 Oct to deny the enemy infiltration and movement through the valley.
10. Execution: Chronological Account of Significant Events;
August
16 At 161302H, 1st Battalion 4th Marines arrived at Dong Ha Combat Base. At 161445H, Company A departed the Dong Ha area for Cam Lo and arrived at 161520H. At 1630H Company B assumed the defense of the TAOR of Dong Ha, at 161630H, Company A assumed responsibility of the TAOR of Cam Lo.
18 At 180930H one sqd from Company D provided security for tank convoy to 2nd Battalion 4th Marines CP. At 181435H, a Marine from Company A purchased a ‘Coke’ from a young Vietnamese female. The ‘Coke’ was found to contain glass slivers.
19 At 190930H 1st Battalion 4th Marines received an order from 4th Marines to provide one platoon for tank security. Tanks were displaced from YD 984564 to Cam Lo. Tank security platoon remained at YD 345699 for the night.
20 At 202049H, a Company A patrol returned with one VCS who was turned over to the local (Cam Lo) ARVN unit.
21 At 210830H Company B provided one squad for security for wire laying team, laying a landline from Dong Ha to Cam Lo. At 211315H they apprehended three VCS and turned them over to CIT.
22 At 221014H a Company A patrol received sniper fire from YD 124582. Patrol apprehended 1 VCS that had a carbine round in his pocket. At 221100H 1st and 3rd platoons of Company B, 3rd Engineers were placed in direct support of 1st Battalion 4th Marines.
23 At 230630H, Company A, 1st battalion 4th Marines and Company C, 3rd Tank Bn departed for a recon in force to the northeast of Cam Lo. At 230650H, a four-man sniper unit and a radio relay team was dispatched by helicopter to Con Thien outpost at YD 116701. At 230840H four 107mm mortars were airlifted to Con Thien outpost. At 231305H, the tank/infantry unit was hit by anti-tank weapons and machine gun fire at YD 131727. Tanks returned 90mm fire and .50 cal fire, destroying AT weapons and an estimated 9 VC KIA (probable); 1 USMC KIA. At 231330H they received mortar fire at YD 135722; 10 USMC WIA’s were Med-evaced from this position. At 231410H the sniper team located at YD 116701 fired on 2 VC entering house at YD 131707 resulting in 1 VC KIA (confirmed). At 231430H, one tank hit a mine. At 231600H, the tank/infantry unit was again hit by mortar fire at YD 122658. 3 USMC WIA were med-evaced from that position. At 231848H Company A provided a unit for tanks (one disabled by an AT mine, two operable) that were located at YD 110608.
24 At 240745H, the three tanks, which remained at YD 110608 overnight, resumed moving towards their CP. At 241825H one tank hit an AT mine at YD 134664. The tank was badly damaged. At 242117H one platoon from Company D arrived at the tanks position to provide security.
25 At 251325H, the platoon from Company D was reinforced by a company of ARVN tanks. At 251555H a USMC tank towing the disabled tank hit another AT mine with slight damage. At 251812H all three tanks arrived at the tank company position at Cam Lo.
26 260342H, Company A reported that they were under attack. At 260347H Company A requested a flare ship to provide illumination. Flare ship was dispatched. At 260352H Company A reported that friendly lines has been penetrated and requested another company to reinforce them. Company D was put on 100% alert at 260405H. At 260440H Company A requested emergency resupply of ammunition. At 260610H Company D reported they were at the helo pad ready for air lift. At 260625H Company A reported lines restored, all secure and requested med-evac helo’s for casualties. At 260830H Company A reported 3 USMC KIA, 13 USMC WIA, 76 VC KIA (confirmed), 1 VCC, 1 VCS captured and 90 enemy weapons captured. At 260830H Company D commenced helo lift to sweep area south of Company A. Company D returned from sweep at 261607H.
30 At 300930H all companies departed Dong Ha/Cam Lo area for a reconnaissance in force to be conducted in an area bounded by grid line YD 98 (west), 63 (north), 56 (south) and YD 10 (east). There was negative contact during this reconnaissance in force.
September
5 At 1000H the Battalion returned to Dong Ha and resumed the Defense of the perimeter.
8 At 1230H the Battalion established a perimeter defense grid square YD 9756 in the Thon Son Lam Area. The mission was to conduct patrols, establish ambushes and prevent enemy movement into or through the area of operations.
10 At 1535H, Battalion CP (XD 973566) received 40-60 rounds 81/82 and 120mm mortar fire. Enemy 120mm mortar positions located at XD 965593; artillery, indirect tank, and 81mm mortar fire returned. AO reported good coverage of target. At 1625H, Company D OP was bracketed by 4 rounds 81/82mm mortar fire, believed to be mortars located at XD 968576, artillery and 81mm mortar fire returned.
11 At 1000H, 1st Battalion 4th Marines assumed OpCon of the Howtar 107mm mortar Battery, 3rd Battalion 12th Marines located within the Battalion perimeter.
12 At 1820H, Company B patrol detonated a mine at XD 962566. Two USMC WIA’s were evacuated by helo.
15 At 1200H Companies B and D departed Battalion perimeter to conduct a reconnaissance in force along ridge line in grid squares XD 9661, 976-, 9861, 9961. At 1315H a Company A patrol discovered a VC filling canteen in stream at XD 994569. Patrol initiated firefight; swept area finding 7 VC KIA (confirmed).
16 At 1125H Company D received S/A, A/W fire from undetermined number of NVA at XD 961601. Marines returned fire and by 1300 were heavily engaged. At 1410H Company B in trace of Company D, received S/A fire from undetermined number of NVA. Companies B and D consolidated positions and established a perimeter at XD 962605.
17 At 0630H Med-evac helo’s, attempting to land in LZ at XD 961601 received heavy S/A and A/W fire. Artillery missions and an air strike were called. At 0715H Companies B and D began receiving heavy S/A and A/W fire. At 0750H they received 81/82mm mortar fire. Companies were unable to move at this time. Continuous air and artillery ‘box me in’ missions were called throughout the remainder of the day, and night. At 0920H Battalion CO’s OP at XD 978588, received 10 rounds incoming 81/82mm mortar fire. AO in area spotted position at XD 979611; 81mm mortars and artillery fired counter-mortar missions; enemy mortar fire ceased, weapon destroyed. At 1230H a resupply helo was disabled in LZ at XD 961601 by enemy S/A and A/W fire. At 1630H Battalion CP received 6 81/82mm mortar rounds. Fire was returned with 81’s and 2 air strikes were directed against suspected mortar position at YD 956586. Good coverage of target reported by aircraft, results unknown.
18 At 1547H, lead elements of 2nd Battalion 7th Marines linked up with Companies B and D. 2/7 units integrated in night defense perimeter.
19 At 1630H Companies B and D returned to Battalion perimeter. At 1900H the Companies were debriefed and the following cumulative enemy casualty figures for 16 August – 19 Sept determined: 259 KIA (confirmed), 369 KIA (probable), 1 VCC, 1 VCS captured.
21 At 0345H the OP on ‘The Rock Pile’ (XD 979559) received 3 incoming grenades and A/W fire from XD 978558. Grenades and A/W fire returned; results unknown. At 1530H an H&S Company patrol made contact with 3 VC at XD 965558; VC fired 15-20 rounds S/A; patrol returned fire with 100-150 rounds S/A fire and the VC broke contract. Patrol swept the area with negative results. Between 1445H and 1600H Battalion CP received approximately 32 rounds 81/82mm mortar fire. An enemy mortar position was located at XD 954585. An air strike was requested and controlled by the AO; the position was 95% destroyed.
22 At 1830H Company B lines sighted 2 VC at XD 967564. VC taken under fire by snipers; VC withdrew to cave. Cave taken under fire by 106’s; results unknown.
24 At 1705H Battalion CP received 8-10 rounds of 57mm recoilless rifle fire. .50 cal. MGs, 106’s, tanks, and mortars returned fire at suspected enemy location silencing the fire.
25 At 0930H, a helo carrying lead elements of Battalion CP group received 2 rounds 81/82mm mortar fire in LZ while attempting to land. Helo was hit by fragments but returned to CP position. At 1835H the Battalion CP received approx. 50 rounds 57mm RR rifle fire. 106’s, tanks, and mortars returned fire at suspected positions resulting in one large secondary explosion, 2 AT weapons destroyed.
28 At 1600H 1st Battalion 4th Marines assumed OpCon of Company G, 2nd Battalion 7th Marines.
29 At 0700H Company G departed Battalion CP to recover 7 MIA’s vicinity XD 925578. At 2330H Company G returned to perimeter. 6 MIA’s were recovered and evacuated by helo.
30 At 1000H Company G departed the Battalion perimeter to return to Dong Ha; Chopped OpCon to 2nd Battalion 7th Marines
October
1-31 The Battalion returned to Dong Ha on 1 October and assumed responsibility for perimeter defense of the Combat Base. Improvement and coordination of units manning the perimeter was the main effort during October. Company D was assigned the defense of an artillery position at Con Thien from 061820H to 101400H. A platoon from Company D provided security for a bridge near Cam Lo at YD 148604. Company A established a defensive perimeter for a Naval Supply Activity at the mouth of the Cua Viet River at YD 346696 from 10 to 31 Oct 1966. In addition, on two occasions, 11 and 12 Oct, a (rein) platoon from Company B provided tank escort for tanks proceeding from Dong Ha to Con Thien. On 12 Oct the tanks and the escorting platoon were ambushed at YD 136667 by an unknown number of enemy. Five VC KIA were confirmed and several weapons ammunition were captured.
11. Results
A total of 285 VC KIA confirmed and 380 probable were credited during the operation. One VC was captured. Ninety nine (99) automatic and semi-automatic weapons were captured and thousands of rounds of ammunition, hand grenades, and booby traps destroyed. A large amount of enemy 782 gear, and numerous documents were also captured.
The areas in which air strikes were made were not searched out except in those places where strikes were held in direct support of our units. Many areas hit by air were inaccessible to friendly forces.
12. Administration Matters
a. The move from Phu Bai to Dong Ha was made by convoy on 16 Aug 66. Between 24 and 28 August two LCU’s were provided to the battalion for transportation of the remaining organic vehicles to the Dong Ha area. Clothing in quantities sufficient to provide a minimum level of acceptance for field operations was provided by the FLSU.
(1) Resupply in the Dong Ha and Cam Lo area was by vehicle.
(2) Resupply in the field was by helo, and averaged 10-12 Tons per day.
b. Casualty Evacuation. All casualties were evacuated efficiently and rapidly with minimum time delay with the exception of the period 16 Sept to 19 Sept when the LZ for B and D Companies was under heavy fire. During this period evacuation was difficult with many helo’s receiving hits from enemy fire and resulting in one helo being disabled in the landing zone.
c. Maintenance. All maintenance within the 1st and 2nd echelon capability was conducted. Equipment requiring higher echelon maintenance, and communications equipment, were evacuated with replacements returning in a normal period of time.
e. Communications. No adverse problems. Some jamming of nets was encountered. The PRC 25’s worked well and held up excellently.
13. Special Equipment and Techniques. None
15. Commanders Analysis.
a. The overall performance of the Battalion was excellent. It is felt that one weak company commander and a weak S-4 Section kept us out of the outstanding category.
b. The artillery support rendered by 3/12 was outstanding. Their fires were responsive, accurate and of sufficient volume.
c. Close Air support was outstanding. Their fires were responsive, accurate and of sufficient volume.
d. Helicopter support was average. Much difficulty was experienced in being able to get choppers to land when and where desired. However, it must be noted, that some of the pilots were extremely motivated and courageous.
e. It is felt that the best offensive tactics in this operation was to make contact, back off, hit the enemy hard with supporting fires and repeat the process, until the objective is taken.
f. It is felt that the enemy is often times prone to permit lead units to pass through the outer perimeter of the enemy positions in an attempt to split friendly forces. If a second unit is employed closely behind the lead unit, when the enemy opens fire, the second unit can quickly drive in, link up with the lead unit and either be behind the enemy or be surrounded by the enemy. Either case being advantageous, if properly executed and sufficient supporting fires are available. It is not felt that a well-disciplined and highly motivated unit of company size or larger should fear encirclement.
15. Recommendations
a. That a chopper be made available to Battalion Commanders for reconnaissance and control when their units are committed.
b. That ‘digging in’ deeply be stressed at all levels.
c. That Infantry Battalions carry at least one lister bag per platoon to catch water. This can be easily done by stretching a poncho over the lister bag.
d. That Infantry Battalions have on hand at all times, sufficient 81mm illumination for self use until artillery illumination or a flare ship can be obtained.
e. That at least three days of battery supplies for all radios be on hand at all times.
f. That sufficient pyrotechnics be on hand at all times for marking targets and for marking company and platoon positions when operating under canopy.
g. That Infantry Battalions not try to wear flack jackets in a fast moving situation in hot weather.
This page last corrected 25 August 2011