The U.S. Army Campaigns of the Vietnam War

TAKING

THE

OFFENSIVE

OCTOBER 1966–

SEPTEMBER 1967
CMH Pub 76–4

Cover: Members of the 1st Cavalry Division (Airmobile) landing on a hilltop during Operation Lejeune in 

1967. (National Archives)
by

Glenn F. Williams

Center of Military History

United States Army

Washington, D.C., 2016

TAKING

THE

OFFENSIVE

OCTOBER 1966–

SEPTEMBER 1967

5

Introduction

To many Americans, the war in Vietnam was, and remains, 

a divisive issue. But fifty years after the beginning of major U.S. 

combat operations in Vietnam, well over half the U.S. population 

is too young to have any direct memory of the conflict. The massive 

American commitment—political, economic, diplomatic, and 

military—to the mission of maintaining an independent and nonCommunist South Vietnam deserves widespread attention, both 

to recognize the sacrifice of those who served and to remember 

how those events have impacted our nation.

U.S. involvement in Southeast Asia began after World War II 

when elements of the Vietnamese population fought back against 

the reimposition of French colonial rule. Although the United 

States generally favored the idea of an independent Vietnam, 

it supported France because the Viet Minh rebels were led by 

Communists and U.S. policy at that point in the Cold War sought to 

contain any expansion of communism. France’s defeat in 1954 led 

to the division of Vietnam into a Communist North (Democratic 

Republic of Vietnam) and a non-Communist South (Republic of 

Vietnam). The United States actively supported the latter as it dealt 

with a growing Communist-led insurgent force (the Viet Cong) 

aided by the North Vietnamese. The initial mission of training 

South Vietnam’s armed forces led to deepening American involvement as the situation grew increasingly dire for the Republic of 

Vietnam.

By the time President Lyndon B. Johnson committed major 

combat units in 1965, the United States already had invested thousands of men and millions of dollars in the effort to build a secure 

and stable Republic of Vietnam. That commitment expanded 

rapidly through 1969, when the United States had over 365,000 

Army soldiers (out of a total of a half million troops of all services) 

in every military region of South Vietnam with thousands of other 
6 

Army personnel throughout the Pacific area providing direct 

support to operations. The war saw many innovations, including 

the massive use of helicopters to conduct airmobile tactics, new 

concepts of counterinsurgency, the introduction of airborne 

radio direction finding, wide-scale use of computers, and major 

advances in battlefield medicine. Yet, as in most wars, much of 

the burden was still borne by soldiers on the ground who slogged 

on foot over the hills and through the rice paddies in search of 

an often elusive foe. The enormous military effort by the United 

States was, however, matched by the resolve of North Vietnamese 

leaders to unify their country under communism at whatever 

cost. That determination, in the end, proved decisive as American 

commitment wavered in the face of high casualties and economic 

and social challenges at home. Negotiations accompanied by the 

gradual withdrawal of U.S. forces led to the Paris Peace Accords in 

January 1973, effectively ending the American military role in the 

conflict. Actual peace was elusive, and two years later the North 

Vietnamese Army overran South Vietnam, bringing the war to an 

end in April 1975.

The vast majority of American men and women who went 

to Vietnam did so in the uniform of the United States Army. They 

served their country when called, many at great personal cost, 

against a backdrop of growing uncertainty and unrest at home. 

These commemorative pamphlets are dedicated to them.

JON T. HOFFMAN

Chief Historian
7

Taking the Offensive, October 

1966–September 1967

In early 1966, the head of the U.S. Military Assistance 

Command, Vietnam (MACV), General William C. Westmoreland, 

controlled some 185,000 U.S. troops in South Vietnam. Over the 

last eighteen months he and his South Vietnamese allies had 

checked the growth of the Communist insurgency and were now 

poised to begin making progress across a wide front—political, 

economic, psychological, and military. With a robust logistical 

network in place and another 200,000 U.S. troops expected to 

arrive by the end of 1967, Westmoreland told his superiors that the 

allied strategy for the coming year “will be one of a general offensive.” Although the primary mission of the U.S. and Free World 

Military Assistance Forces from South Korea, Australia, and 

New Zealand would be “destroying VC/NVA [Viet Cong/North 

Vietnamese Army] main forces and base areas,” they would also 

support the South Vietnamese pacification program designed 

to eradicate Viet Cong influence at the village and hamlet level. 

“The 1967 combined campaign plan,” Westmoreland reported, “is 

based on the concept that the war in Vietnam is a single war” 

requiring the U.S. and South Vietnamese to apply a wide range of 

military, economic, and political measures suited to the particular 

conditions of each region and locality.

Westmoreland expected several years of hard fighting before 

the Communist threat was contained. The enemy fielded around 

131,000 full-time soldiers belonging to the indigenous People’s 

Liberation Armed Forces (PLAF), also known as the Viet Cong, and 

to the North Vietnamese People’s Army of Vietnam (PAVN). The 

North Vietnamese and some of the Viet Cong soldiers belonged 

to conventional “main force” units. These formations were wellequipped with modern Chinese and Soviet weapons and operated 

under the control of North Vietnamese regional headquarters 

known as Front commands. The remainder of the full-time Viet 

Cong soldiers formed what were known as “local force” units. 
8

These were smaller and generally less well-armed than main force 

units, and operated under the control of province- or district-based 

committees. Backing the conventional units were an additional 

113,000 hamlet-based guerrillas and 39,000 Viet Cong political 

cadre who provided the regulars with food, recruits, and intelligence. 

North Vietnam poured thousands of fresh soldiers and hundreds of 

tons of supplies onto the southern battlefield each month via the 

Ho Chi Minh Trail, and Viet Cong cadre drew manpower, taxes, 

and food from nearly 40 percent of South Vietnam’s population. 

All of the enemy forces in South Vietnam came under the control 

of North Vietnam’s Communist Party and its principal decisionmaking body, the politburo, composed of a dozen senior officials 

who ran the country at the behest of Ho Chi Minh, now elderly, 

infirm, and living in semiretirement (Map 1).

The United States waged a strategic bombing campaign 

against North Vietnam designed to pressure Hanoi into withdrawing its support for the Viet Cong, but Operation Rolling 

Thunder had yet to weaken the enemy’s resolve. Even so, the 

air campaign and several others that targeted the Ho Chi Minh 

Trail in neighboring Laos had made it harder and more expensive for North Vietnam to move troops and supplies into the 

South. Westmoreland’s superior, Commander in Chief, Pacific 

(CINCPAC), Admiral Ulysses S. Grant Sharp Jr., controlled the 

strike aircraft which were based in Thailand and on carrier groups 

in the South China Sea, though President Lyndon B. Johnson 

imposed buffer zones around sensitive areas—downtown Hanoi, 

the port of Haiphong (the off-loading point for Soviet cargo 

ships), the Vietnamese-Chinese border—and vetted the target 

list himself. The president therefore tended to use the bombing 

program as an extension of his diplomatic efforts, varying its 

scope and intensity to reflect the perceived status of back-channel 

discussions between the governments in Washington and Hanoi, 

not the military situation on the ground. 

Westmoreland enjoyed substantial but not unlimited 

authority when it came to fighting the war in South Vietnam. 

Ambassador Henry Cabot Lodge Jr., the head of the U.S. mission, 

was technically the highest-ranking American official in South 

Vietnam. Lodge usually deferred to the general on military 

matters, while Westmoreland extended the same courtesy to the 

ambassador in political affairs.The head of MACV served as the 

principal military adviser to the South Vietnamese government, 
Ho C h i M i n h Tr a i l

B4 FRONT

B1 FRONT

B3 FRONT

B2 FRONT

B5 FRONT

Tonle Sap

GULF

O F

TONKIN

GULF

O F

SIAM

SOUTH

CHINA

SEA

Red R

Black R

Mekong R

Mekong R

DEMARCATION LINE

HAINAN

Con Son

Phu Quoc

Haiphong

Dien Bien Phu

Vinh

Dong Hoi

Hue

Da Nang

Pleiku

Qui Nhon

Quang

Ngai

Quang Tri

Kontum

Da Lat

Nha Trang

Cam Ranh

Tay Ninh

Bien Hoa

Vung Tau

Sihanoukville

Can Tho

Loc Ninh

HANOI

VIENTIANE

BANGKOK

PHNOM PENH

SAIGON

BURMA

NORTH

VIETNAM

CHINA

CHINA

THAILAND

LAOS

CAMBODIA SOUTH

VIETNAM

INDOCHINA

1966–1967

0 150

Miles

Communist Front Boundary

Map 1
10 

but lacked the authority to command South Vietnamese forces or 

remove corrupt and incompetent leaders. Westmoreland likewise 

had little authority over South Vietnam’s pacification program 

which aimed to bring economic development and security to 

rural hamlets at risk of falling under Viet Cong control. Another 

component of the U.S. mission, the United States Agency for 

International Development (USAID), delivered the lion’s share 

of economic development and humanitarian assistance funds 

($275 million in 1965 and over twice that amount in the first 

nine months of 1966). Hoping to bring the various aid programs 

under more effective supervision, Lodge established the Office of 

Civil Operations in November 1966 to coordinate the actions of 

all U.S. civilian agencies in Vietnam supporting revolutionary 

development. 

Political considerations at home prevented Westmoreland 

from intensifying the war beyond a certain point. The growing 

cost of the war—some 5,700 U.S. troops had already died, and 

another 26,800 had been wounded—steadily eroded public 

support. The president’s refusal to mobilize the nation’s reserve 

components meant that MACV’s maximum strength would 

likely top out at around 500,000 men. Johnson would not 

allow Westmoreland to strike the enemy’s sanctuaries in Laos 

and Cambodia with conventional ground forces, fearing such 

attacks would destabilize the pro-Western governments in both 

countries. The MACV commander did monitor the Communist 

supply network in Laos and Cambodia using small reconnaisThe 173d Airborne Brigade advance on a wood line in War Zone D. National Archives
11

sance teams from the MACV Studies and Observation Group 

(MACV–SOG), but the existence of that program was kept a 

tightly held secret. Likewise, the president ruled out any conventional ground attack into North Vietnam out of concern that 

the Soviet Union and China would formally enter the war on 

Hanoi’s behalf. Despite the restrictions he faced and the obstacles he had to overcome, Westmoreland hoped his 1966–1967 

campaign would begin to swing the momentum of the war in 

the favor of the allies. 

Strategic Setting

Keeping to the campaign strategy that General Westmoreland 

had developed with his South Vietnamese counterparts the previous year, the allies divided responsibility for fighting the war 

based on their respective capabilities. South Vietnamese forces 

took the lead in the heavily populated rural areas and in the cities, 

devoting most of their attention to battling local Viet Cong units 

and rooting out Communist political cadre and guerrillas. U.S. 

combat forces used their superior mobility, engineer support, and 

firepower to seek out and destroy enemy regulars in the remote 

forests and mountains while also neutralizing the base areas 

and infiltration routes that supported them. For the upcoming 

northeast monsoon season—the period from November to May 

when the prevailing winds brought dry weather and clear skies 

to the lower half of South Vietnam—Westmoreland intended 

to mount large search and destroy operations in the provinces 

north and west of the capital at Saigon. His goal was to reduce 

the threat that several large Communist jungle bases posed to 

the capital region, the political, economic, and military heart of 

the South Vietnamese government. Meanwhile, he would use the 

soon-to-arrive U.S. 9th Infantry Division and the 199th Infantry 

Brigade (Light) to strengthen the shield immediately around the 

city. Farther north, other Army units would continue to defend 

the vast interior of the Central Highlands and shield the foodrich, densely populated coastal plains, while U.S. Marine forces 

defended the Demilitarized Zone that bordered North Vietnam 

and protected the major cities in the northernmost provinces. By 

the spring of 1967, the MACV commander hoped to be wearing 

down the enemy’s combat strength faster than he could replace it, 

while South Vietnam’s government steadily reclaimed people and 

territory from Viet Cong control. 
12 

General Westmoreland had a good understanding of 

Communist military thinking based on the thousands of enemy 

documents that MACV had captured in recent years. The 

Communists divided the battlefield into three general categories: 

the agrarian lowlands where most of the rural population lived 

and where most of the food was produced; the hinterlands, the 

remote and sparsely populated mountains, forests, and swamps 

that covered three-quarters of South Vietnam; and the cities, the 

administrative, military, and commercial centers. In late 1963, the 

First Secretary of the Lao Dong Party and the dominant figure 

in Hanoi, Le Duan, had instructed his principal commander 

in the South, General Nguyen Chi Thanh, to crush the South 

Vietnamese Army with an aggressive main force war and to 

attack Saigon itself when the conditions were right. This policy, 

which relegated the local force and guerrilla units to a supporting 

role, remained in place even after the United States began sending 

combat units to Vietnam in the spring of 1965. Unlike the South 

Vietnamese forces, U.S. combat units were able to fight in the 

remote jungles and mountains which had formerly been enemy 

safe zones. General Thanh lost his chance to take Saigon, but 

insisted on continuing the main force war despite the heavy 

casualties it incurred in order to preserve his logistical network 

in the hinterlands and to shield the local Viet Cong units in the 

countryside. Now with the dry season beginning in the lower half 

of the country, Westmoreland expected to see an upsurge in the 

fighting as U.S. units pushed into the wilderness areas where the 

Communist regulars were based.

By October 1966, Westmoreland commanded approximately 

325,000 personnel in South Vietnam, including around 200,000 

members of the U.S. Army. Close to half of those soldiers belonged 

to combat or combat support units, organized around four divisions (three infantry and one airmobile), three separate infantry 

or airborne brigades, and one armored cavalry regiment, forming 

a total maneuver force of fifty battalions backed by thirty artillery 

battalions and sixty-two aviation companies. The remaining half 

of the U.S. Army in Vietnam consisted of combat service support 

units, handling a range of logistical, administrative, and technical 

missions, plus a force of nearly 10,000 advisers who worked with 

South Vietnamese units and provincial governments in hundreds 

of locations around the country. The MACV commander also 

controlled twenty U.S. Marine Corps maneuver battalions, and 
13

indirectly controlled twenty-one South Korean and two Australian 

maneuver battalions, giving him a total maneuver force of ninetythree combat battalions. 

The standard U.S. infantry battalion had an authorized 

strength of 920 officers and enlisted men, organized into four 

infantry companies, one heavy weapons platoon, and a command 

group. The average Army brigade in Vietnam consisted of three 

battalions—infantry, mechanized, or armor—plus a field artillery battalion and a host of smaller support units to accomplish 

signal, engineering, medical, supply, and other tasks. In late 1966, 

most U.S. infantrymen carried the M16 assault rifle, a lightweight 

but powerful weapon that fired a 5.56-mm. bullet from a twentyround magazine, while others were armed with the older and 

heavier M14 rifle that fired a 7.62-mm. bullet from a twenty-round 

magazine. The Army intended to replace all of the M14s with M16s 

as soon as U.S. factories produced sufficient numbers, but the 

initial production model of the M16 had proven unreliable—the 

rifle tended to jam from unburned powder or debris accumulating 

in the firing chamber. A new variant with a chromed chamber 

and other improvements, the M16A1, would begin reaching U.S. 

soldiers in early 1967, equipping all U.S. infantry units and a few 

select South Vietnamese units by the end of the year. 

Westmoreland organized U.S. ground forces into intermediate field commands which generally paralleled South 

Vietnamese corps headquarters. The U.S. officer in charge of 

each field command served as the principal adviser to his South 

Vietnamese counterpart. In the I Corps Tactical Zone, the III 

Marine Amphibious Force directed operations in South Vietnam’s 

five northernmost provinces from the port of Da Nang, employing 

a combat force built around the 1st and 3d Marine Divisions and 

working in coordination with a South Korean marine brigade. 

Based at the coastal town of Nha Trang, the I Field Force headquarters controlled U.S. operations across the twelve provinces 

of II Corps, using the 1st Cavalry Division (Airmobile), the 4th 

Infantry Division, and the 1st Brigade of the 101st Airborne 

Division as its principal weapons, assisted by two South Korean 

infantry divisions. The II Field Force headquarters based at Long 

Binh, northeast of Saigon, ran U.S. operations in III Corps with 

a combat maneuver force built around the 1st Infantry Division, 

the 25th Infantry Division, the 173d Airborne Brigade, the 196th 

Infantry Brigade (Light), and the 11th Armored Cavalry. The II 
14 

Field Force also coordinated the operations of a brigade-sized 

Australian–New Zealand task force (Map 2).

The Army of the Republic of Vietnam consisted of some 

275,000 soldiers in the autumn of 1966, organized around ten light 

infantry divisions, twenty ranger battalions, four armored cavalry 

groups, and eight separate battalions of artillery. Smaller and less 

well-equipped than their U.S. counterparts, these units generally 

operated in limited areas near major centers of population. To deal 

with emergency situations, the South Vietnamese Joint General 

Staff in Saigon controlled a strategic reserve of six airborne and 

five marine battalions that could be deployed to any part of the 

country on short notice. Part of this strategic reserve force was 

typically stationed in one of four National Priority Areas, one 

in each corps zone, that the government had identified as being 

critical to the country and therefore in need of extra resources to 

strengthen rural security and economic development. The head of 

the Joint General Staff, General Cao Van Vien, coordinated South 

Vietnamese operations through General Westmoreland, who 

served as his principal adviser.

In addition to the regular ground forces, another 320,000 

lightly armed soldiers belonging to the Regional and Popular 

Forces performed local security duties under the control of 44 

province and 242 district chiefs. Around 16,000 personnel served 

with the South Vietnamese Air Force, while a similar number of 

troops belonged to the coastal-oriented South Vietnamese Navy. 

Finally, some 30,000 Mon-Khmer tribesmen from the highlands of Vietnam fought as local militia under the control of the 

1,200-man U.S. Army 5th Special Forces Group and its South 

Vietnamese counterpart. Commonly referred to as Montagnards, 

these irregulars manned border surveillance and security posts. 

Remote and vulnerable, those outposts had often been the target 

of Communist attacks, and would prove to be so again in the year 

to come.

Operatio

In October 1966, II Field Force Commander Lt. Gen. 

Jonathan O. Seaman set in motion the dry season campaign for 

III Corps, the South Vietnamese tactical zone that encompassed 

eleven provinces between the southern foothills of the Central 

Highlands and the northern edge of the Mekong Delta. He 

ordered the 25th Infantry Division with four attached brigades 
15

 Map 2

Tonle

 Sap

GULF OF

THAILAND

SOUTH

CHINA SEA

SOUTH CHINA SEA

Mekong R

Mekong R

III CTZ

IV CTZ

I CTZ

II CTZ

DEMARCATION LINE

LAOS

THAILAND

CAMBODIA

NORTH

 VIETNAM

SAIGON

Corps Tactical Zone Boundary

National Priority Area

Operational Priority Area

1966–1967

SOUTH VIETNAM

CORPS TACTICAL ZONES

0

0 150

150 Kilometers

Miles
16 

to sweep the rubber plantations and triple-canopy rainforests 

of Tay Ninh Province, northwest of the capital, and to comb 

through the enemy-held jungles in Hau Nghia Province west 

of Saigon. Meanwhile, he instructed the 1st Infantry Division, 

reinforced by the 173d Airborne Brigade and elements of the 

11th Armored Cavalry, to wear down enemy base areas in Binh 

Duong Province north of Saigon. II Field Force would support 

those maneuver units with the 23d and 54th Artillery Groups, 

the 12th Aviation Group, and the 921st Engineer Group. General 

Seaman relied on his counterpart, Lt. Gen. Nguyen Bao Tri, to 

safeguard the populated areas of III Corps using three South 

Vietnamese infantry divisions, five ranger battalions, and three 

armored cavalry squadrons backed by hundreds of smaller 

Regional and Popular Forces units. The independent, brigadesized 1st Australian Task Force reinforced the allied position 

east of Saigon (Map 3).

Attleboro Begins

In mid-September, Brig. Gen. Edward H. de Saussure’s 

196th Brigade began a series of battalion-sized probes in 

southern Tay Ninh Province named Operation Attleboro. 

When 25th Division units uncovered a large cache of rice in 

the Saigon River Valley about thirty kilometers southeast of 

Tay Ninh City, the commander of the 25th Division, Maj. Gen. 

Frederick C. Weyand, who was also the acting II Field Force 

commander in General Seaman’s absence, ordered de Saussure 

to move his battalions farther up the Saigon River in search of 

more stockpiles. One battalion redeployed to the district town 

of Dau Tieng on 19 October, and four days later uncovered a 

shed complex housing a large stockpile of rice. After discovering other large caches, de Saussure received permission from 

Brig. Gen. George G. O’Connor, acting commander of the 25th 

Division in Weyand’s absence, to reinforce Attleboro with 

a second battalion from the 196th Brigade on 1 November, 

putting an infantry battalion from the 25th Infantry Division 

under his control.

Over the next three days, the two battalions from de 

Saussure’s brigade and a shuttle of helicopters managed to fly out 

only a portion of the huge rice haul. When a captured document 

revealed the locations of other supply bases hidden in the forests 

about ten kilometers north of Dau Tieng, General O’Connor 
17

directed de Saussure to spend one more day recovering rice and 

then to destroy what he could not evacuate. On the morning 

of 3 November, de Saussure marched his two battalions north 

from Dau Tieng, advancing in four groups across a wide front to 

drive enemy forces before them. Simultaneously, de Saussure air 

assaulted the infantry battalion that he controlled from the 25th 

Map 3

OPERATION ATTLEBORO 14 Sep–24 Nov 66

OPERATION

CEDAR FALLS

8–26 Jan 67

OPERATION FAIRFAX

30 Nov 66–14 Dec 67

OPERATION JUNCTION CITY 22 Feb–14 May 67

BIEN HOA CU CHI

DI AN

LONG BINH

BEAR CAT

SUOI DA

XUAN LOC

VUNG TAU

ARVN

XXX

III

25

X X

9

X X

1

X X

XXX

II FF

IV CTZ

II CTZ

 CAPITAL MILITARY DISTRICT

WAR ZONE C

FISH HOOK

WAR ZONE D

IRON TRIANGLE

SOUTH CHINA SEA

14

20

15

13

1

1

4

4

4

4

22

PHUOC TUY

BINH TUY

BINH

THUAN

LONG KHANH

PHUOC LONG

BINH

DUONG

HAU

NGHIA

LONG AN

GO CONG

KIEN HOA

KIEN TUONG

DINH TUONG

GIA DINH

TAY

NINH

BIEN HOA

QUANG DUC

BINH LONG LAM DONG

VINH BINH

VINH LONG

An Loc

Loc Ninh

Dau Tieng

SAIGON

CAMBODIA

Corps Tactical Zone Boundary

Engagement

1966–1967

III CORPS TACTICAL ZONE

0 50 Miles

0 50 Kilometers
18

Infantry Division to the east and west of de Saussure’s advancing 

battalions to catch any Communist forces that might try to 

outflank the 196th Brigade. General de Saussure’s third battalion 

remained in reserve at Tay Ninh (Map 4). 

Nothing went as the 196th Brigade commander planned. 

The brigade’s four advancing columns and the two flanking units 

became disoriented in the dense jungle and thick elephant grass, 

losing track of where the other units were located. About 1200, a 

unit from the 101st PAVN Regiment ambushed a patrol from the 

25th Division on the American western flank, inflicting heavy 

casualties. General O’Connor reinforced the embattled troops 

with two more companies from his 25th Infantry Division delivered by helicopter. Meanwhile, de Saussure airlifted his third 

battalion from Tay Ninh City to Dau Tieng and then marched 

half of it north to join his other soldiers who were heavily 

engaged with a regiment from the 9th PLAF Division. As night 

approached, the American troops consolidated into two perimeters about a kilometer from one another, the first commanded 

by Maj. Guy S. Meloy and the other by Lt. Col. Hugh H. Lynch. 

In the morning the units in both locations untangled and reorganized themselves from the previous night’s confusion and 

continued their missions. 

Unbeknownst to General de Saussure, U.S. operations 

had disrupted General Thanh’s plans. Thanh headed the 

Central Office for South Vietnam (COSVN), an extension of 

North Vietnam’s politburo that ran all Communist affairs 

in the lower half of South Vietnam and adjacent areas of 

Cambodia. He had hoped to blunt a dry-season push into 

the Communist base areas of northern III Corps by tying 

U.S. forces down with an offensive of his own. Accordingly, 

he had ordered the commander of the 9th PLAF Division, 

Senior Colonel Hoang Cam, to “destroy a ‘vital’ element of 

the enemy” in the provinces north of Saigon, and to support 

the local insurgent forces and political infrastructure by 

widening “friendly” and “liberated areas.” The COSVN chief 

had also directed Cam to protect the important logistical 

base area in northern Tay Ninh Province known as War Zone 

C. Given those requirements, Cam had decided to attack the 

inexperienced 196th Infantry Brigade, as well as the South 

Vietnamese Civilian Irregular Defense Group (CIDG) and 

territorial units located nearby. 
Map 4

2 25

X

2 1

X

3 1

X

1 28

I I

1 28

I I

196(-)

X

1

X X

25

X X

196

X

21–22 Nov

12 Nov

11–15 Nov

24 Nov

TRAI BI

TAY NINH

WEST

TAY NINH CITY

DAU TIENG

Special Forces Camp

SUOI DA

BEN CUI

Special Forces Camp

PREK KLOK Special Forces Camp

KATUM

Special Forces Camp

WAR ZONE C

19 Nov

10 Nov

15 Nov

6 Nov

8 Nov

4–5 Nov

4–5 Nov

4 Nov

Prek Klok

Saigon R

Saigon R

Suoi Ba Hao

Song Vam Co Dong

4

4

26

239

19

13

13

14

244

246

247

246

22

22

MICHELIN

PLANTATION

Old French Fort

PLENTITUDE

Bo Tuc

Ap Suoi Tre

Ap Gu

Sroc Con Trang

Suoi Cao

Tay Ninh Dau Tieng

HAU NGHIA

BINH LONG

BINH DUONG

TAY NINH

TAY NINH

C A M B O D I A

S O U T H

V I E T N A M

C A M B O D I A

S O U T H

V I E T N A M

OPERATION AT TLEBORO

THEATER OF OPERATIONS

3–24 November 1966

Ground Movement

Air Assault

Engagement

0

0 5 10 Kilometers

Miles 5 10
20 

Colonel Cam had planned to initiate his offensive on 3 

November using two Viet Cong regiments from the 9th PLAF 

Division and one from the 7th PAVN Division, reinforced by a Viet 

Cong local force battalion. While one Viet Cong regiment struck 

the 196th Brigade’s newly established base to the west of Tay Ninh 

City in an attempt to lure out and annihilate its reaction force, 

two battalions from the second Viet Cong regiment, joined by the 

Viet Cong local force battalion, would attack South Vietnamese 

outposts at Suoi Cao, thirty kilometers to the southeast. The 

remaining Viet Cong battalion and the North Vietnamese 

regiment from the 7th PAVN Division would conduct the main 

attack on the Suoi Da Special Forces camp, fifteen kilometers 

northeast of Tay Ninh City. 

As the Americans advanced on 3 November, Colonel Cam 

quickly adjusted his plans. Seeing an opportunity to strike the 

196th Infantry Brigade while it was exposed, he canceled the 

attack on the Suoi Da Special Forces camp. He likewise downgraded the attacks on Tay Ninh and Suoi Cao to diversions. If 

all went well, these thrusts would confuse the Americans and 

facilitate Cam’s new objective—the destruction of de Saussure’s 

brigade.

Cam’s diversionary efforts caused confusion in the allied 

camp but achieved little else. The South Vietnamese at Suoi Cao 

easily rebuffed the assault on their position with the help of U.S. 

air and artillery, while the attack on Tay Ninh never materialized. With most of his combat units in the heavy woods near 

the Ba Hao northwest of Dau Tieng, Cam sent an additional 

battalion to reinforce one that occupied a prepared fortified 

stronghold, complete with concrete bunkers and interconnecting tunnels, less than 500 meters northwest of the western 

American laager.

On the morning of 4 November, General de Saussure 

instructed Meloy to bring half of his force northeast to link up 

with Colonel Lynch as the remainder of his troops continued 

their northward sweep. Meloy’s group had only traveled a few 

hundred meters when its lead company walked into an ambush 

that enemy soldiers from the 9th Division had prepared the 

night before. U.S. artillery had little effect, and attacks on the 

left and right flanks not only failed to dislodge the enemy, but 

resulted in all the U.S. companies becoming pinned down and 

taking heavy casualties. Meloy requested reinforcements as the 
21

enemy continued to attack. Colonel Lynch sent a company to 

link up with Meloy, but after those troops got into a fight with 

Viet Cong soldiers well short of their destination, de Saussure 

ordered the company to return to Lynch’s position. 

Four hours later, and after three human wave assaults 

nearly overran Meloy’s position, a fresh infantry company from 

the 25th Division air assaulted into a landing zone just to the 

west of the ambush site. It failed to break the enemy cordon, 

sustaining heavy casualties including the battalion and company 

commanders. Meloy’s men were unable to fight their way 

through from the other side. With the situation deteriorating, 

General Weyand ordered the commander of the 1st Infantry 

Division, Maj. Gen. William E. DePuy, to assume control of the 

battle. DePuy moved elements from his 3d Brigade to Soui Da 

on the evening of 4 November and established his own forward 

command post at Dau Tieng. General DePuy ordered the four 

committed infantry battalions to break contact and to consolidate themselves into a single perimeter under the command 

of Major Meloy, who had proven to be the best officer on the 

ground, and then wait for the arrival of two infantry battalions 

from the 1st Infantry Division the next morning.

The fighting resumed early on 5 November as the 9th 

Division made a final attempt to isolate and overwhelm part of 

the U.S. force. Major Meloy kept his troops organized, throwing 

back the assault and then pursuing the retreating enemy. Hard 

fighting continued for several hours as the American soldiers, 

reinforced by two battalions from the 1st Infantry Division, 

pushed their way through Viet Cong bunker complexes that the 

enemy used as staging areas. A pair of soldiers from Company 

A, 2d Battalion, 27th Infantry, 25th Infantry Division, Capt. 

Robert F. Foley and Pfc. John F. Baker Jr., were later awarded the 

Medal of Honor for rescuing many of their wounded comrades 

while advancing through enemy fire and knocking out multiple 

bunkers, ignoring the grenade wounds that both had received 

in the process. 

On 6 November, General DePuy sent the 196th Brigade 

back to Tay Ninh City to recover while he continued his pursuit 

of the 9th Division and 101st Regiment. General Weyand elevated 

Attleboro to a Field Force operation and instructed General 

O’Connor to deploy his 2d Brigade, 25th Infantry Division, with 

four battalions to assist General DePuy’s 2d and 3d Brigades. 
22 

On 10 November, O’Connor’s 2d Brigade, commanded by 

Col. Thomas M. Tarpley, headed north. Meanwhile, DePuy air 

assaulted five of his battalions to locations north and northeast 

of Suoi Da. When none of DePuy’s battalions made significant 

contact, he ordered the 1st Battalion, 28th Infantry, to prepare 

for extraction so it could be committed elsewhere. As the 

unit waited to be picked up by helicopter, an enemy company 

attacked the northern part of its position. The Americans 

drove the foe back with heavy losses. A short while later, the 

North Vietnamese renewed the attack from the northwest, 

but the Americans again repulsed their assault. Despite losses, 

the enemy regimental commander sent a second battalion 

against the Americans’ western and southwestern flanks. The 

Communist units, committed piecemeal, never penetrated the 

perimeter and subsequently disengaged. Col. Edwin H. Marks’ 

3d Brigade attempted to cut off their retreat, but the enemy 

escaped. The next day, U.S. soldiers found many dead enemy 

strewn around their perimeter, and discovered more hidden in a 

tunnel complex where they also found a huge supply base, which 

may have explained the intensity of the enemy attack. 

Colonel Cam’s forces were in full retreat by 8 November, 

heading back to the safety of Cambodia. General O’Conner’s 

2d Brigade, 25th Infantry Division, pursued the enemy nearly 

to the border but located only abandoned base camps and 

a few Communist units who fought delaying actions before 

vanishing. When Attleboro ended on 24 November, a total 

of eighteen U.S. and three South Vietnamese infantry battalions had participated, making it the largest allied operation 

of the war to date. The sweep had forced the 9th Division to 

abandon its planned attack on the Suoi Da Special Forces camp 

in order to defend its own bases and depots. Enemy losses were 

counted as 1,016 soldiers killed in action, but U.S. commanders 

believed they had inflicted heavier casualties than the official 

total given the enemy’s practice of removing the dead after a 

battle. Although DePuy recommended that the II Field Force 

continue its sweep of War Zone C, Weyand believed that it was 

unwise to keep several U.S. brigades out in the remote wilderness if the enemy refused to give battle. The acting II Field Force 

commander returned the units to their normal operational 

areas, a move that General Seaman endorsed when he resumed 

the Field Force command at the end of November. 
23

The B3 Front in the Central Highlands

In the autumn of 1966, the I Field Force commander, Lt. 

Gen. Stanley Larsen, defended the western highlands of II 

Corps—Kontum, Pleiku, and Darlac Provinces—with two reinforced brigades under the control of the 4th Infantry Division. 

The division’s commander, Maj. Gen. Arthur S. Collins, maintained his headquarters at Camp Enari, just south of Pleiku City, 

which served as the rear base for his 2d Brigade, 4th Infantry 

Division, the attached 3d Brigade of the 25th Infantry Division, 

the 1st Squadron, 10th Cavalry, and most of the 1st Battalion, 69th 

Armor. General Collins used those eight maneuver battalions, 

reinforced by the 52d Artillery Group, the 52d Aviation Battalion 

(Combat), and the 937th Engineer Group (Combat), to deal with 

the half-dozen North Vietnamese regiments that operated in the 

western highlands. 

Collins’ main supply route, Highway 19, extended east across 

the highland plateau from Pleiku City to An Khe, the rear base 

of the 1st Cavalry Division, and then down to the coastal port of 

Qui Nhon, a total distance of around 130 kilometers. In addition 

to the materiel provided by the 8th Transportation Group (Motor 

Transport) from the U.S. Army Support Command, Qui Nhon, to 

the 45th General Support Group in Pleiku City, the U.S. Seventh 

Air Force and I Field Force aviation units brought additional 

troops and supplies to the U.S. airfields near Pleiku City, Kontum 

City, and Ban Me Thuot in Darlac Province.

A North Vietnamese headquarters known as the B3 Front

controlled enemy regulars in the western highlands. The six regiments protected a logistical network that moved supplies from 

Laos and Cambodia across the mountainous plateau to enemy 

base camps along the central coast. A second tactical headquarters known as the B1 Front controlled the Communist main force 

units on the central coast of II Corps and southern I Corps. Both 

front commands reported to the Military Region 5 headquarters, 

which controlled and coordinated all of the enemy’s political and 

military affairs in those two sectors (Map 5).

Given the enormous size of the western highlands (some 300 

kilometers long and 100 kilometers wide) and its rugged, forestcovered terrain, General Collins relied on timely intelligence 

to anticipate and then to respond to enemy threats. His main 

task was to shield provincial and district capitals that lay along 

Highway 14, a paved road that ran from north to south through 
Map 5

CAP ROK

X X

ARVN

XXX

II

4

X X

1 101

X

9 ROK

X X

XXX

I FF

FWD

XXX

ROK

1

X X

2 7

X

NHA TRANG

NINH HOA

TUY HOA

BAN ME THUOT

PLEI ME

DUC CO

CAMP ENARI AN KHE

PHU CAT

QUI NHON

FSB BIRD

PLEIKU

KONTUM

DAK TO

PLEI DJERENG

CAM RANH BAY

PHAN RANG

PHAN THIET

OPERATION PAUL REVERE IV 20 Oct–30 Dec 66

OPERATION THAYER II

25 Oct 66–12 Feb 67 

OPERATION GERONIMO 31 Oct–4 Dec 66

B1 FRONT

B3 FRONT

B2 FRONT

III CTZ

I CTZ SOUTH CHINA SEA

14

14

20

21

19

1

1

1

1

11

14

Dao Phu Qui

QUANG TIN

QUANG NGAI

KONTUM

BINH DINH

PLEIKU

PHU BON

PHU YEN

DARLAC

KHANH HOA

QUANG DUC TUYEN DUC

BINH THUAN

PHUOC

LONG

LAM DONG

BINH TUY

LONG

KHANH

PHUOC TUY

NINH

THUAN

Phu My

CAMBODIA LAOS

Corps Tactical Zone Boundary

Communist Front Boundary

Engagement

1966–1967

II CORPS TACTICAL ZONE

0 50 Miles

0 50 Kilometers
25

the middle of the Central Highlands. Larsen’s counterpart, Lt. 

Gen. Vinh Loc, controlled two infantry regiments, an armored 

cavalry group, and a three-battalion ranger group in western 

II Corps, but those units lacked the equipment and training to 

operate in the remote mountains. Fortunately, most of the towns 

on Highway 14 lay between thirty and fifty kilometers from the 

border, giving Collins a sizable buffer zone. The 4th Infantry 

Division commander counted on the fact that enemy offensives 

never happened quickly. Trails had to be hacked out of the jungle 

and forward staging areas built. With few civilians in the area, 

enemy soldiers had to carry nearly all of their own supplies on 

foot. Food was also scarce, and U.S. aircraft sprayed chemical 

defoliants over suspected farming sites to prevent the enemy 

from growing his own food. As a result, the Communist troops 

in western II Corps could not live off the land as their counterparts did on the fertile coast. Enemy soldiers would often labor for 

weeks or even months to pre-position enough supplies for a major 

battle, giving U.S. reconnaissance elements—Montagnard patrols 

operating from a dozen U.S. 5th Special Forces Group border 

surveillance camps, long-range reconnaissance teams attached 

to I Field Force, fixed-wing surveillance aircraft equipped with 

infrared and chemical detectors, helicopter-infantry scout teams, 

and radio intercept detachments—ample time to detect those 

preparations. 

Hoping to eliminate some of I Field Force’s best sources of 

intelligence, the B3 Front ordered the 1st PAVN Division and the 

95B PAVN Regiment to attack a pair of Special Forces camps—

Plei Djereng, about forty kilometers west of Pleiku City, and Duc 

Co, twenty kilometers farther south and east of the Plei Trap 

Valley—which blocked the most convenient infiltration routes 

into southwestern Pleiku Province. In late September 1966, 

the Communists began moving supplies from Cambodia into 

the Plei Trap Valley, and then to staging areas near the Special 

Forces camps.

The commander of the 4th Infantry Division, General 

Collins, caught wind of the threat on 14 October when a 

Montagnard scout company ran into a large North Vietnamese 

force near Plei Djereng. When the enemy stood and fought, and 

then resumed the battle the next day, Collins suspected that the 

B3 Front was attempting to pin down the Montagnard units at 

Plei Djereng prior to an attack on the camp itself. On 16 October, 
26 

he ordered one of his two main maneuver units, the 3d Brigade, 

25th Infantry Division, commanded by Col. James G. Shanahan, 

to move into the hills around Plei Djereng. Over the next five days, 

Shanahan’s men encountered small groups of soldiers from the 

95B Regiment and found evidence that two regiments from the 

1st PAVN Division had also moved into the area. With hard intelligence in hand, Collins dispatched Col. Judson F. Miller and the 

2d Brigade, 4th Infantry Division, to Plei Djereng, committing all 

six of his infantry battalions to a search and destroy operation he 

dubbed Paul Revere IV.

For the first week of the operation, U.S. troops found abandoned camps and used trails in the hills around Plei Djereng but 

no enemy units. That changed on the night of 27–28 October when 

the North Vietnamese attacked four of the U.S. companies in their 

night defense positions. The fighting lasted on and off for three 

days, resulting in 138 enemy killed and 22 U.S. troops dead. Eager 

to trap the three North Vietnamese regiments before they could 

withdraw into Cambodia, General Larsen moved the 2d Brigade, 

1st Cavalry Division, commanded by Col. George Casey, from the 

central coast to Duc Co so General Collins could concentrate his 

forces in the Plei Trap Valley.

The six battalions of Collins’ two brigades advanced 

relentlessly and forced the enemy to give ground and abandon 

supplies. To guard against the possibility of a North Vietnamese 

unit slipping past the U.S. advance to attack Plei Djering, Lt. Col. 

Eleazer Parmly deployed two battalion-sized groups of Special 

Forces-led CIDG troops into the area. Parmly personally led 

Task Force Prong to screen the western approaches to the Special 

Forces camp, while Task Force North conducted surveillance 

along the northern limit of Collins’ advance. On 10 November, 

an element of Task Force Prong was patrolling a kilometer from 

Cambodia when a North Vietnamese unit that Maj. Gen. Chu 

Huy Man held in reserve, the 88th PAVN Regiment, lunged across 

the border to pick it off. The CIDG soldiers held their ground 

with assistance from U.S. air and artillery strikes, but their 

casualties were heavy. General Collins air assaulted a battalion 

from Miller’s 2d Brigade into the contact area, helping the CIDG 

troops withdraw to a more defensible location three kilometers 

from the border. The 4th Infantry Division commander also 

did not want any U.S. troops to cross the border inadvertently, 

which could create a political crisis. General Collins ordered 
27

Shanahan’s 3d Brigade to continue its northern advance through 

the Plei Trap Valley while the remainder of Miller’s 2d Brigade 

headed west on foot to support Task Force Prong. 

The next day, 11 November, Colonel Miller established 

Firebase Red Warrior at the spot where his infantry battalion 

had regrouped with Task Force Prong, also flying in an artillery 

battery to provide those troops with additional firepower. The 

enemy reacted swiftly. On the evening of 12 November, North 

Vietnamese mortars bombarded the firebase, and then waves of 

Communist infantry assaulted Red Warrior from the north and 

west. The defenders repulsed the savage, all-night attack at a cost 

of five killed and forty-one wounded. When morning came, the 

defenders found seventy-six enemy dead on the outskirts of the 

firebase. Not wishing to risk more fighting so near the border, 

Collins abandoned the base and had another one established 

farther east.

On 18 November, elements from the 2d Brigade and Task 

Force Prong found two huge, abandoned enemy bases in the 

southern Plei Trap, and Collins directed Colonel Miller to destroy 

them. As allied soldiers were exploring the camps, the 33d PAVN 

Regiment emerged from the surrounding jungle, attacking from 

three directions at once. The U.S. infantrymen held the enemy 

at bay throughout the afternoon, continuing to fight until the 

North Vietnamese withdrew in the early morning hours of 19 

November. Allied losses came to nineteen killed, including 

a squad leader from Company C, 1st Battalion, 14th Infantry, 

Sgt. Ted Belcher, who received the Medal of Honor for jumping 

on an enemy grenade to save the lives of his squad members. 

General Collins decided the time had come to withdraw Miller’s 

2d Brigade from the southwestern Plei Trap Valley. Miller was 

not finding large supply caches to destroy, and the enemy could 

attack him at will from his Cambodian sanctuaries without fear 

of being pursued. 

While Colonel Miller was shifting his forces farther east, 

Colonel Casey of the 2d Brigade, 1st Cavalry Division, screened 

his movement by inserting company-sized elements to check 

reported enemy sightings. On 21 November, one of the companies encountered a North Vietnamese battalion, which immediately attacked and overran one of the U.S. platoons. The 

Communists executed their American prisoners before withdrawing under bombardment from U.S. aircraft and artillery. 
28 

Troopers later swept the area and found it strewn with enemy 

bodies. Unwilling to risk another such debacle, General Larsen 

instructed Casey to return both of his battalions to Binh Dinh 

Province. 

Once all of the U.S. units had departed the lower Plei Trap 

Valley, Larsen saturated the area with B–52 strikes for the next ten 

days. Meanwhile the two brigades controlled by the 4th Infantry 

Division continued to search the northern part of the valley, 

hoping to regain contact with the North Vietnamese regiments 

still believed to be in the area. On 9 December, General Larsen 

reinforced Paul Revere IV with the 1st Brigade, 101st Airborne 

Division, and General Loc committed several South Vietnamese 

battalions to aid in the search. When the allies failed to locate any 

major targets after nearly two weeks, Larsen ended the operation 

on 27 December and redeployed all of his units to their traditional 

sectors. 

Guarding the Central Coast

As the 4th Infantry Division hunted B3 Front regiments 

in the western highlands during the final months of 1966, 

General Larsen conducted other operations in the coastal 

lowlands of II Corps where 80 percent of the region’s people 

lived and where most of the food was produced. The I Field 

Force commander used the 1st Cavalry Division (Airmobile) 

to combat the 3d PAVN Division in Binh Dinh Province, II 

Corps’ National Priority Area, and two brigades—the 1st 

Brigade, 4th Infantry Division, and the 1st Brigade, 101st 

Airborne Division—to defend smaller Phu Yen Province to its 

south. General Larsen also used the 1st Cavalry Division as his 

theater reserve, because its fleet of nearly 500 helicopters gave 

it the ability to reinforce any sector in II Corps on short notice. 

The South Korean Capital Division helped secure the southern 

part of Binh Dinh Province where Qui Nhon, the main I Field 

Force port and supply depot, and the 7th Air Force fighterbomber airfield at Phu Cat were located. The South Korean 

9th Infantry Division (“White Horse”) worked with South 

Vietnamese forces on the southern coast of II Corps to protect 

Khanh Hoa, Ninh Thuan, and Binh Thuan Provinces, the 

last of those also home to a reinforced battalion from the 1st 

Cavalry Division known as Task Force Byrd. General Larsen’s 

41st Artillery Group and the 17th Aviation Group supported 
29

both U.S. and South Korean forces in all five coastal provinces 

of II Corps. 

On the northern coast of Binh Dinh Province, Maj. Gen. 

John Norton, commander of the 1st Cavalry Division, continued 

his long-running hunt for the 3d PAVN Division in the autumn 

of 1966. His main effort, Operation Thayer II, produced 

few contacts in November and early December as the North 

Vietnamese continued to hide somewhere in the mountains that 

overlooked the Bong Son and Phu My Plains. On 17 December, 

however, elements of the 1st Brigade under Col. James S. Smith 

encountered two North Vietnamese battalions while searching 

the Kim Son Valley, a former Viet Cong stronghold just west of 

Phu My that the South Vietnamese government had begun to 

depopulate by moving the people to safer areas on the coast. The 

Communists had apparently come down into the valley to look 

for food that might have been left behind. Six U.S. rifle companies 

fought a hotly contested battle with the enemy that lasted until 

nightfall. 

The commander of the 3d Division, Col. Le Truc, was not 

willing to surrender his access to the valley and those farmers 

who still remained. He ordered his 22d Regiment to overrun 

one of the 1st Cavalry Division’s landing zones in the Kim Son 

Valley, a company-sized firebase known as Bird. Manned by 

two artillery batteries and one company of infantry, the fortifications at Bird were in poor shape due to the recent monsoon 

flooding. The outpost also lacked protective razor wire and 

listening posts beyond the bunker line, making it an especially 

vulnerable target.

On the evening of 26 December, two North Vietnamese 

battalions moved into assault positions, one of them within 

twelve meters of the U.S. bunker line, without being detected. At 

0100, the North Vietnamese began pummeling the landing zone 

with mortars and recoilless rifles, disorienting the defenders and 

allowing the lead enemy battalion to penetrate the northeastern 

part of Bird. The Communists recoiled, however, when the crew of 

a 105-mm. howitzer fired two “beehive” rounds into the advancing 

North Vietnamese soldiers, shredding them with hundreds of steel 

darts. S. Sgt. Delbert O. Jennings, an infantryman from Company 

C, 1st Battalion, 12th Cavalry, gunned down an enemy sapper 

team that was attempting to destroy another howitzer, raced back 

and forth through the cross fire to reorganize the American lines, 
30 

and then killed a North Vietnamese soldier with the butt of his 

weapon before going in search of wounded Americans, actions 

for which he was awarded the Medal of Honor. The arrival of 

helicopter gunships finally convinced the enemy commander 

to withdraw his forces, having destroyed one artillery piece and 

inflicted severe casualties on the defenders. The next morning, 

elements of the 1st Cavalry Division pursued the retreating 22d 

Regiment, eventually killing a total of 267 of its men either at Bird

or in the days that followed. The 1st Cavalry Division lost twentyseven soldiers killed and sixty-seven wounded in the fight, but the 

enemy had been driven from the Kim Son Valley, allowing the 

South Vietnamese government to complete the evacuation of the 

inhabitants so that they could no longer aid the enemy. 

An UH–1B firing on enemy positions National Archives
31

In Phu Yen Province to the south, the 1st Brigade, 101st 

Airborne Division, and the 1st Brigade, 4th Infantry Division, 

worked with South Vietnamese forces to shield the coastal basin 

around Tuy Hoa, the provincial capital, and the jet-capable 

airfield just south of the city. The major threat came from the 18B

and 95th PAVN Regiments that operated from the coastal hills, 

supported by several Viet Cong battalions in the lowlands. Brig. 

Gen. Willard Pearson, the commander of the 1st Brigade, 101st 

Airborne Division, initiated a search for those regiments on 31 

October 1966 using intelligence that indicated their probable locations. In the opening phase of Operation Geronimo, Pearson sent 

two of his battalions to search a known enemy base area about 

twenty kilometers southwest of Tuy Hoa. The paratroopers hit a 

dry hole, finding evidence that the 18B Regiment had moved out 

of the area a month earlier. 

Shifting to his other target, the 95th Regiment, Pearson air 

assaulted most of his brigade into a second base area northeast of Tuy Hoa on 6 November. Brig. Gen. David O. Byars’ 1st 

Brigade, 4th Infantry Division, shielded the Tuy Hoa lowlands as 

the paratroopers swept east and south across the forested hills. 

One of General Pearson’s battalions overran a fortified North 

Vietnamese camp on 10 November, but Geronimo netted few 

other trophies during the next two weeks. When intelligence 

confirmed that the 95th Regiment had moved far to the west, 

General Larsen sent Pearson’s brigade to the Central Highlands 

to reinforce Operation Paul Revere IV. Operation Geronimo

ended on 4 December, its meager results partly offset by the 

knowledge that the hills around Tuy Hoa were presently clear of 

North Vietnamese units. 

Into the Iron Triangle

After bringing Operation Attleboro to a close in Tay Ninh 

Province at the end of November 1966, General Seaman waited an 

additional two months before making another sweep of War Zone 

C. The delay would enable him to return to the war zone during 

the height of the dry season when the weather would be favorable 

and the enemy at his most active. In the meantime, the II Field 

Force commander decided to target the Iron Triangle, a Viet Cong 

base area that served as the enemy’s principal supply center in 

central III Corps. Communist rear service troops transported war 

material from the Fish Hook region of Cambodia to intermediate 
32 

stations in War Zone C, and then through other camps on the 

east side of the Saigon River before arriving at the Iron Triangle, 

centered thirty kilometers north of Saigon. The Iron Triangle was 

known to contain the Military Region 4 headquarters, COSVN’s 

principal command organ in central III Corps, and served as a 

forward supply base for the 9th PLAF Division as well as several 

Viet Cong local force battalions. Disrupting the Iron Triangle 

would reduce the enemy’s ability to conduct offensive operations 

near Saigon, a key objective for General Westmoreland. 

Named for the geometric shape it resembled, the base area 

occupied some 300 square kilometers of jungle in southern Binh 

Duong Province, its lower vertex pointing dagger-like toward the 

capital. Bounded to the southwest by the Saigon River and to the 

east by Highway 13, the triangle’s northern face extended horizontally through the Dien Thanh forest from the village of Ben 

Suc on the west toward the district capital of Ben Cat to the east. 

General Seaman’s plan, a massive search and destroy operation 

named Cedar Falls, called for six allied maneuver brigades to 

surround the triangle. They would move in rapidly from multiple 

directions to prevent the enemy from escaping and then conduct 

a month-long sweep. U.S. engineer units equipped with powerful 

bulldozers, called Rome plows, and demolition gear would help 

clear vehicle paths and landing zones in the dense jungle. South 

Vietnamese forces would relocate the residents of Ben Suc to more 

secure areas elsewhere in III Corps. Once depopulated, most of 

the Iron Triangle would be turned into a free-fire zone, permitting U.S. forces to fire on suspected targets without first obtaining 

permission from South Vietnamese authorities.

In the first week of January 1967, the 2d Brigade, 25th Infantry 

Division, and the 196th Infantry Brigade established a blocking 

position on the west side of the Saigon River while elements of 

the 1st Infantry Division and the 173d Airborne Brigade moved 

into areas on the periphery of the Iron Triangle, giving those 

movements separate operational names (in the event the enemy 

overheard U.S. radio chatter) to disguise their true purpose. 

Operation Cedar Falls began in earnest on 8 January 1967 when 

the 1st Infantry Division’s 1st and 2d Brigades secured the village 

complex of Ben Suc in the northwestern corner of the triangle, 

while the 1st Division’s 3d Brigade and most of the 173d Airborne 

Brigade extended the cordon around the northeastern corner of 

the triangle. The 11th Armored Cavalry completed the encircle-
33

ment by forming a screen between Ben Cat and the Saigon River, 

cutting the Iron Triangle in two. By the evening of 8 January, all 

six brigades were in place. 

Allied units encountered only scattered resistance from 

guerrillas and rear service troops as they moved into the Iron 

Triangle. A 1st Infantry Division task force secured Ben Suc on 

the first day, opening the way for South Vietnamese authorities 

to enter the village and begin to evacuate its residents. Elsewhere 

in the Iron Triangle U.S. soldiers found hidden supply caches and 

discovered dozens of camouflaged trapdoors that led to a maze 

of underground tunnels and rooms. Soldiers who volunteered 

to explore their depths armed only with a flashlight and a pistol 

became known as “tunnel rats.” Those subterranean scouts recovered a trove of supplies and documents, including some from 

the recently abandoned bunker complex of the Military Region 

4 headquarters. Afterward, U.S. engineers collapsed the tunnels 

with explosives or reported their locations so they could be 

destroyed by B–52 bombers. 

When Cedar Falls ended on 26 January, U.S. and South 

Vietnamese forces had found and destroyed the Military Region 

4 headquarters complex, over 1,000 bunkers, and hundreds of 

tunnels and surface structures. They had captured large quantities 

of weapons, equipment, supplies, ammunition, booby-traps, and 

several thousand tons of rice. The operation netted nearly one-half 

million pages of documents, signal and cryptologic codes, and 

information concerning the enemy’s forces and political infrastructure. Allied forces killed or captured more than 1,000 enemy 

fighters and resettled most of the civilian population to secured 

villages. Nevertheless, the allies knew that they had discovered 

only a portion of the tunnel system, and most of the Iron Triangle 

was still covered in dense jungle, offering the enemy the concealment and the material he needed to build new fortifications. What 

was more, the forced resettlement program had brought hardship 

on thousands of civilians, providing fodder for Viet Cong propagandists. Even with the area depopulated, more operations and 

B–52 strikes would be needed to keep the threat under control.

Returning to War Zone C

At the conclusion of Operation Cedar Falls in late 

January 1967, General Seaman gave his forces several weeks 

to rest and refit before he launched the next and biggest phase 
34 

of his dry season campaign. Named after a town near Fort 

Riley, Kansas, home of the 1st Infantry Division, Operation 

Junction City called for seven U.S. brigades to push into 

northern Tay Ninh Province almost to the Cambodian border 

for a two-month search and destroy mission into War Zone C. 

The II Field Force commander ordered the new commander of 

the 1st Infantry Division, Maj. Gen. John H. Hay Jr., to spearhead the operation with his 1st and 3d Brigades, joining three 

brigades attached to General Weyand’s 25th Division as well as 

the 173d Airborne Brigade and elements of the 11th Armored 

Cavalry. Similar to Cedar Falls, Junction City called for 

U.S. units to encircle the target area—the heart of War Zone C 

as defined to the east by Route 4, to the west by Highway 22, 

and to the north by Route 246—before sweeping specific areas 

within it. Seaman hoped to draw the 9th PLAF Division and 

other COSVN main force units into battle as II Field Force used 

the good weather to search War Zone C more carefully than it 

had done in November during Attleboro. 

The II Field Force commander was eager to disrupt the 

Communist infiltration route that dropped south from the Fish 

Hook through the eastern part of War Zone C before continuing 

along the winding course of the Saigon River to the Iron 

Triangle and other Viet Cong base areas on the outskirts of the 

capital. During the recent Tet holiday truce period from 8 to 12 

February that marked the start of the new lunar year, General 

Westmoreland noted the “dramatic logistical buildup undertaken 

by the North Vietnamese” across the country, including a massive 

push of supplies down the Saigon River infiltration route. General 

Seaman expected Operation Junction City to uncover and 

destroy some of that enemy materiel before it could be used while 

also interdicting the Saigon River trail during the remaining part 

of the dry season.

At first light on 22 February, U.S. helicopters air assaulted 

eight battalions from the 196th Infantry Brigade, the 173d 

Airborne Brigade, and the 1st Brigade, 1st Infantry Division, 

along Route 246, with some units landing within two kilometers of the Cambodian border. A ninth battalion, from the 173d 

Airborne Brigade, conducted a parachute drop from U.S. Air 

Force C–130 transports near the Katum Special Forces camp, the 

first and only large-scale airborne operation of the war. Moving 

up Highway 22, the 3d Brigade, 4th Infantry Division, screened 
35

the western side of War Zone C, while the 3d Brigade, 1st Infantry 

Division, sealed Route 4 along its eastern side, thus creating a 

U-shaped enclosure measuring about twenty kilometers on each 

face. As those blocking elements moved into position, elements 

of the 11th Armored Cavalry and the 2d Brigade, 25th Infantry 

Division, attacked from south to north into the heavily forested 

heart of War Zone C (Map 6). 

Over the next five days, the advancing soldiers discovered a network of small camps and some rear service troops, 

but no main force units or COSVN itself. General Thanh had 

withdrawn his headquarters and three North Vietnamese regiments into the Fish Hook region of Cambodia; rather than 

confront the allied sweep head-on, the COSVN commander 

decided to attack the supply lines that supported the 1st and 

25th Divisions in northwestern III Corps. Thanh ordered his 

regiments in the Fish Hook to swing south to cut Route 4 on 

the eastern side of Operation Junction City. He also ordered 

a 9th Division regiment in War Zone D, some sixty kilometers 

to the east of War Zone C, to cut Highway 13 that supported 

the 1st Division north of Saigon. 

COSVN’s counterattack began on 28 February when a 

battalion from the 101st Regiment ambushed a company from 

the 3d Brigade, 1st Infantry Division, some fifteen kilometers 

north of the Suoi Da Special Forces camp. The engagement on 

Route 4 cost the Americans 25 killed and 28 wounded, while 

the enemy left behind 167 dead. The attack combined with the 

paltry results he was getting inside the Operation Junction 

City horseshoe convinced Seaman to reorient his units. On 1 

March, he moved the 1st Brigade, 1st Infantry Division, and the 

173d Airborne Brigade from their blocking positions on Route 

246 to the eastern side of Junction City. General Hay’s 3d 

Brigade, 1st Infantry Division, remained in place along Route 

4, operating from three main firebases—the Special Forces 

camps at Suoi Da, Prek Klok, and Katum—to guard the main 

U.S. supply route in eastern War Zone C. On the opposite side 

of the dissolving horseshoe, Seaman ordered Weyand to search 

the area west of Highway 22 with elements of his 3d Brigade, 

4th Infantry Division, and to return the 196th Brigade and the 

2d Brigade, 25th Infantry Division, to their bases at Tay Ninh 

City and Cu Chi, respectively. Finally, he instructed the 11th 

Armored Cavalry to make a counterclockwise sweep along the 
Map 6

X

X X

X

X X

X

X

X

X

3 4

X

196

X

2 25

X

1 1

X

3 1

X

11(-)

III

173

X

TRAI BI

TAY NINH

WEST TAY NINH CITY

D

Special Forces Camp

SUOI DA

BEN C

Special Forces Camp

PREK KLOK

Special Forces Camp

LZ GEORGE

FSB GOLD

KATUM

Special Forces Camp

WAR ZONE C

FI

22 Mar

28 Feb

10 Mar

11 Mar

31 

Suoi Ba Hao

Song Vam Co Dong

4

4

26

13

247

246

78

22

22

22 

Old French Fort

PLENTITUDE

Ap Suoi Tre

Ben Soi

Tay Ninh

TAY NINH

TAY NINH

C A M B O D I A

S O U T H

V I E T N A M

OPERATION JUNCTION CITY

PHASE 1

22 Feb–17 Mar

OPERATION JUNCTION CITY

THEATER OF OPERATIONS

22 February–15 April 1966

Ground Movement

Air Assault

Screen

Engagement

0

0 5 10 Kilometers

Miles 5 10
H

DAU TIENG

Special Forces Camp

Special Forces Camp

CUI

MINH THANH

Special Forces Camp

TONG LE CHAN

CHON THANH

AN LOC

QUAN LOI

BEN SUC BEN CAT

LAI KHE

FSB THRUST

FSB PARRY

FSB CHARLIE

IRON TRIANGLE

ISH HOOK

30–31 Mar

 Mar–1 Apr

Saigon R

Saigon R

239

19

13

13

14

244

245

246

13

13

13

MICHELIN

PLANTATION

Ap Bau Bang

Ben Cat

Ben Suc

Dau Tieng

An Loc

HAU NGHIA

BINH LONG

BINH DUONG

C A M B O D I A

S O U T H

V I E T N A M

OPERATION JUNCTION CITY

PHASE 2

18 Mar–16 Apr
38 

boundary of Operation Junction City to secure the roads that 

ringed War Zone C. 

The shift brought an increase in fighting on the eastern 

side of War Zone C. On 3 March a battalion from the 70th 

Guard Regiment attacked a company from the 173d Airborne 

Brigade near Katum, and on 10 March the 272d Regiment

launched a savage assault on a 1st Infantry Division firebase 

near the Prek Klok Special Forces camp. The two engagements 

cost the enemy around 250 killed for a loss of 23 American 

lives. On 11 March, an element of the 101st Regiment attacked 

the 173d Airborne Brigade east of Prek Klok, resulting in a 

three-day skirmish that reduced the enemy’s force by fifty 

men. Those attacks were probably designed to buy time for 

Viet Cong rear service troops to move out of the area with 

everything they could carry. U.S. soldiers found a number of 

recently abandoned camps as they searched the forests east of 

Route 4, including one that had been the National Liberation 

Front’s radio broadcast site. 

On 18 March, General Seaman initiated phase two of 

Operation Junction City by establishing a new horseshoe to the 

An Air Force C–130 drops supplies to ground forces during Operation Junction Cit

National Archives
39

east of the original zone. Route 4 became the western side of the 

new horseshoe, stretching thirty kilometers from Suoi Da to Katum. 

The northern face extended forty kilometers east from Katum to 

An Loc via Route 246. Highway 13 south of An Loc formed the 

eastern side of Operation Junction City II. The new commander 

of the 25th Infantry Division, Maj. Gen. John C. F. Tillson, placed 

the 196th Brigade in a blocking position on Route 4 and ordered 

the 3d Brigade, 4th Infantry Division, to search the western side 

of Junction City II. General Hay put his 1st and 2d Brigades on 

Route 246, and sent engineers to build a new Special Forces camp, 

Tong Le Chon, at the halfway point to monitor the upper reaches 

of the Saigon River infiltration corridor in eastern War Zone C. 

General Hay stationed the newly arrived 1st Brigade, 9th Infantry 

Division, along Highway 13, and sent the 173d Airborne Brigade 

into the heart of the new horseshoe. Hay retained one squadron 

from the 11th Armored Cavalry, the other two having gone back to 

eastern III Corps, giving him and General Tillson a total of twentyfour maneuver battalions for this second phase of the operation.

General Thanh reacted fiercely to the presence of so many 

U.S. combat units athwart his main supply channel into III Corps. 

On the night of 20–21 March, the 273d Regiment, 9th Division,

and guerrillas attacked a U.S. night position on Highway 13, 

eight kilometers north of Lai Khe, manned by Troop A of the 3d 

Squadron, 5th Cavalry, and a battery of 105-mm. howitzers. The 

assault failed, costing the enemy at least 227 soldiers killed and 

putting the 273d Regiment out of action. U.S. losses were three 

killed and sixty-three wounded, with two armored personnel 

carriers destroyed and five tanks and eleven armored personnel 

carriers damaged. The next evening on the other side of the 

Junction City II zone, two battalions from the 272d Regiment

assaulted Firebase Gold, located near Soui Tre hamlet about 

fifteen kilometers northeast of the Suoi Da Special Forces camp, 

and manned by 450 troops from the 3d Brigade, 4th Infantry 

Division. Advancing waves of Viet Cong soldiers penetrated the 

southwest perimeter about 0800, but artillerymen stopped their 

advance with a blast of beehive rounds. The situation became 

critical fifteen minutes later when the enemy penetrated the 

northeast sector, but a flight of U.S. fighter-bombers and a relief 

force of tanks and infantry arrived just in time to disrupt the 

attack. The shattered 272d Regiment beat a hasty retreat, leaving 

behind 647 dead, as well as many weapons and large quantities of 
40 

ammunition. Westmoreland later described the battle at Firebase 

Gold as “one of the most successful single actions of the year.” 

With two regiments knocked out of action for no appreciable 

gain, General Thanh decided to bide his time before committing 

his remaining forces. The COSVN commander allowed General 

Hay’s 1st and 2d Brigades of the 1st Infantry Division to move into 

position on Route 246 virtually unopposed and to begin building 

a string of firebases while U.S. engineers began work on the Tong 

Le Chon Special Forces camp, located approximately halfway 

between Katum and An Loc. 

On 24 March 1967 General Seaman passed the II Field Force 

baton to Lt. Gen. Bruce Palmer, who in turn notified Generals Hay 

and Tillson to begin winding 

down Operation Junction 

City II. The six-brigade 

sweep through War Zone 

C had yet to produce satisfying results. U.S. troops had 

located numerous camps, 

but most were empty. Booby 

traps, mines, and sniper fire 

had produced a steady trickle 

of casualties, and the logistical burden of supporting 

so many brigades in the 

remote wilderness of War 

Zone C was putting a strain 

on II Field Force’s aviation, 

vehicle, and maintenance 

capacities. General Palmer 

was about to start pulling 

units out of the sector when 

his intelligence learned that 

one or more COSVN regiments were moving toward 

the U.S. positions on Route 

246. Suddenly the fight was 

back on.

The enemy made his 

first move on the afternoon 

of 31 March when elements 

A reconnaissance team extracted by helicopter.National Archives
41

of COSVN’s security unit, the 70th Guard Regiment, attacked a 

patrol from Lt. Col. Alexander Haig’s 1st Battalion, 26th Infantry, 

which was operating from Landing Zone George approximately ten kilometers southeast of Katum. Believing that a larger 

enemy attack was imminent, Colonel Haig pulled his men back 

to George, which they manned with another infantry battalion 

from the 1st Infantry Division. 

His hunch proved to be correct. Early on 1 April, the fresh 

271st Regiment and the 70th Guard Regiment attacked Landing 

Zone George while mortars bombarded the other 1st Division 

firebases along Route 246. The men at George were well dug-in, 

having constructed bunkers along the perimeter that featured full 

overhead cover and firing slits to the front and oblique angles, but 

the Viet Cong pressed onward through the murderous cross fire. 

The enemy penetrated the northwestern perimeter to a depth of 

seventy-five meters before the weight of U.S. air strikes, automatic 

weapons fire, and helicopter gunships finally proved too much. 

The attackers retreated, leaving behind some 600 dead. U.S. 

casualties numbered 17 killed and 102 wounded. The fight for 

Col. James A. “Alex” Grimsley (left), 2d Brigade, 1st Infantry Division, and Lt. Col. Alexander 

Haig (right), 1st Battalion, 26th Infantry, confer during Operation Junction City I

National Archives
42 

George wrecked Thanh’s last remaining main force unit in the 

area. Thereafter, the enemy kept his distance, surrendering for the 

moment control of War Zone C. 

General Palmer kept his forces in the region for another 

two weeks before ending Junction City II on 15 April. All told, 

the two-month operation had destroyed 5,000 enemy structures, 

captured more than 800 tons of food and supplies and a halfmillion pages of documents, and killed over 2,700 enemy soldiers. 

It had dealt the 9th Division a serious beating and disrupted 

COSVN’s main supply channel into III Corps, but the arrival of 

the wet season meant that U.S. forces would not be able to operate 

in War Zone C for another six months, giving the enemy time to 

recover from his wounds. II Field Force would need to return in 

even greater strength and for a longer period of time next year in 

order to make a decisive impact in III Corps. 

Despite the failure to achieve all the intended goals, the operations in War Zones C and D helped secure III Corps’ more populated 

areas by keeping the enemy’s major combat units otherwise occupied. 

Of particular concern for the allies was III Corps’ National Priority 

Area—the city of Saigon, Gia Dinh Province, which enveloped the 

capital, and neighboring portions of Binh Duong, Hau Nghia, Long 

An, Phuoc Tuy, and Bien Hoa Provinces. This region contained nearly 

3 million people and was the heart of South Vietnam’s political, 

military, and economic apparatus. The allies could not win the war 

without maintaining a firm hold over this area. Thus, while the 1st 

and 25th Divisions pressed against the enemy’s fortified bases to the 

north and west, other allied elements worked in the rear to improve 

the security of the National Priority Area.

Most of the burden for protecting the National Priority 

Area fell on the South Vietnamese 5th, 18th, and 25th Infantry 

Divisions, assisted by Regional and Popular Forces and various 

police formations. When the 11th Armored Cavalry joined II 

Field Force in October 1966, Seaman stationed the unit in Bien 

Hoa Province to the east of Saigon because the relatively dry and 

flat land offered suitable conditions for its armored vehicles. The 

area west and south of the capital was much wetter, inundated 

for part of the year and crisscrossed with rivers and canals. The 

II Field Force commander relied on his 25th Infantry Division 

based at Cu Chi, Hau Nghia Province, to assist South Vietnamese 

forces in that area as circumstances permitted, but there were not 

enough U.S. troops to spare for a sustained effort. 
43

To correct this deficiency, Westmoreland obtained the 199th 

Infantry Brigade (Light) in late December 1966, stationing the 

unit at Long Binh and ordering it to work with South Vietnamese 

forces in Gia Dinh Province. Operation Fairfax, which began in 

late December, paired U.S. and South Vietnamese troops at the 

battalion and company level throughout Gia Dinh. As the MACV 

commander described the concept to his superiors, Fairfax was 

designed to “root out the VC infrastructure and pave the way for 

Revolutionary Development” in the critical districts surrounding 

Saigon so the enemy could no longer get within striking range 

of the capital and other critical facilities like Tan Son Nhut Air 

Base and Long Binh Post by relying on the local population for 

food, shelter, and information. Westmoreland looked forward to 

getting more help in January 1967 when the 9th Infantry Division 

began to arrive from the United States. He planned to place that 

division’s three brigades along Saigon’s eastern and southern 

flanks, thereby completing the perimeter of U.S. divisions around 

the capital and its environs. 

Eager to get more results from South Vietnam’s pacification 

program, managed by the Ministry of Revolutionary Development 

with only minimal assistance from MACV, and better performance out of the South Vietnamese Army, President Johnson 

traveled to the island of Guam on 20–21 March 1967 to speak 

with South Vietnam’s Chief of State General Nguyen Van Thieu 

and Prime Minister Nguyen Cao Ky. The president brought with 

him the experienced diplomat Ellsworth Bunker, who was slated 

to replace Ambassador Lodge in May, and his national security 

adviser, Robert Komer, who would soon take charge of a new 

MACV directorate called the Civil Operations and Revolutionary 

Development Support (CORDS) that would supervise all U.S. 

efforts related to the pacification program. The formation of 

CORDS would end years of fragmented control and unify U.S. 

support of pacification under MACV’s umbrella, with Komer 

serving as Westmoreland’s deputy for revolutionary development. 

To assist Westmoreland, President Johnson announced in 

April 1967 that General Creighton W. Abrams, the Army vice 

chief of staff, would become Westmoreland’s deputy at MACV. 

General Abrams would also play an active role in training 

and modernizing the South Vietnamese Army as well as the 

Regional and Popular Forces units that provided the first line 

of defense in many rural areas. With Komer working on paci-
44

fication and Bunker handling political affairs, particularly 

South Vietnam’s transition from a state ruled by a military 

committee to a democratic nation governed by elected officials 

and a written constitution, General Westmoreland would now 

be able to focus more of his attention on the military challenges of defeating the Communists. 

Renewed Fighting in II Corps

On 3 January 1967, Maj. Gen. William R. Peers took 

command of the 4th Infantry Division, replacing General Collins 

as the principal U.S. commander in the western highlands. Like 

his predecessor, Peers believed it was necessary to engage the 

enemy as soon as he crossed the border so the B3 Front would 

burn through supplies and manpower that otherwise might reach 

Communist units on the populated central coast. When allied 

intelligence learned that the enemy had returned to the Plei Trap 

Valley early that February, two months after the conclusion of 

Operation Paul Revere IV, Peers obtained permission from 

General Larsen to mount another sweep through the southwestern corner of Pleiku Province. 

The 4th Division commander gave the leading role of 

the new mission, Operation Sam Houston, to Col. James B. 

Adamson and his 2d Brigade. On 12 February, Colonel Adamson 

sent two infantry battalions into the Plei Trap Valley. The 32d

and 66th PAVN Regiments contested the incursion with short 

but savage company- and battalion-sized attacks, withdrawing 

each time before U.S. forces had an opportunity to fix the enemy 

in place. By 15 February, U.S. losses had grown to 55 killed and 

74 wounded, while Adamson’s 2d Brigade counted about 300 

enemy dead (Map 7). 

Seeing that the North Vietnamese had adjusted their tactics, 

Peers modified his own. The 4th Infantry Division commander 

began using B–52 strikes as his primary offensive weapon, 

hitting areas in the valley that aerial observation, radio intercepts, and long-range reconnaissance patrols indicated might 

contain enemy forces. To assess the results of the bombing and 

to cover a wider search area, Peers got permission from General 

Larsen to reinforce Sam Houston with two battalions from the 

1st Brigade, 4th Infantry Division, commanded by Col. Charles 

A. Jackson. Even with those reinforcements, the operation 

produced meager results. General Peers’ decision to operate 
Map 7

NHA TRANG

NINH HOA

TUY HOA

BAN ME THUOT

PLEI ME

DUC CO

CAMP ENARI AN KHE PHU CAT

QUI NHON

FSB BIRD

PLEIKU

KONTUM

GIA VUC

BA TO

LZ ENGLISH

DAK TO

DAK SEANG

PLEI

 DJERENG

CAM RANH BAY

PHAN RANG

PHAN THIET

OPERATION SAM HOUSTON 12 Feb–5 Apr 67

OPERATION FRANCIS MARION 6 Apr–11 Oct 67

OPERATION GREELEY 17 Jun–11 Oct 67

OPERATION PERSHING 11 Feb 67–19 Jan 68

III CTZ

I CTZ

B1 FRONT

B3 FRONT

B2 FRONT

SOUTH CHINA SEA

14

14

20

21

19

1

1

1

1

11

14

Dao Phu Qui

QUANG TIN

QUANG NGAI

KONTUM

BINH DINH

PLEIKU

PHU BON

PHU YEN

DARLAC

KHANH HOA

QUANG DUC

TUYEN DUC

BINH THUAN

PHUOC

LONG

LAM DONG

BINH TUY

LONG

KHANH

PHUOC TUY

NINH

THUAN

Phu My

CAMBODIA LAOS

Corps Tactical Zone Boundary

Communist Front Boundary

Engagement

1967–1968

II CORPS TACTICAL ZONE

0 50 Miles

0 50 Kilometers
46 

near the border almost backfired on 27 February when a helicopter mistakenly landed a scout team in Cambodia. The team 

got into a skirmish but the helicopter extracted it without any 

loss once the error had been recognized. Fortunately for Peers, 

the matter blew over without sparking a political crisis. Contact 

in the Plei Trap Valley remained sporadic until 12 March when 

U.S. troops discovered several battalions from the 88th PAVN 

Regiment in a bunker complex, sparking a fierce battle that cost 

the Americans fourteen killed and forty-six wounded. After 

losing an estimated 200 dead, the enemy escaped across the 

Cambodian border. 

General Peers expanded the Operation Sam Houston sector 

on 16 March when Montagnard trail watchers and U.S. long-range 

reconnaissance patrols reported North Vietnamese troops in the 

Plei Doc Valley, fifteen kilometers south of the Plei Trap Valley. 

Colonel Jackson sent two battalions from his 2d Brigade to investigate. Disaster struck late on 21 March when a battalion from the 

95B Regiment overran a long-range reconnaissance patrol in the 

Plei Doc Valley. Two U.S. infantry companies rushed to the area 

but arrived too late. The North Vietnamese attacked the relief force 

and then withdrew into Cambodia, leaving behind 136 of its dead. 

U.S. losses came to twenty-seven killed and forty-eight wounded. 

In addition, Communist forces in the Plei Trap Valley ambushed 

a company from Colonel Adamson’s 1st Brigade, killing twentytwo Americans and wounding fifty-three, for minimal losses of 

their own. 

With the monsoon season approaching, General Peers 

began winding down Operation Sam Houston. By 5 April all 

of his forces had left the Plei Trap and Plei Doc Valleys. Like its 

predecessor Paul Revere IV, Sam Houston had prevented the 

B3 Front from building a base in southwestern Pleiku Province 

that could be used to attack Pleiku City or the Special Forces 

camps that screened the border. The operation also tied down 

at least three enemy regiments during the height of the dry 

season, stopping them from hitting more vulnerable targets 

elsewhere. On the other hand, Sam Houston had cost the 4th 

Infantry Division over 200 more killed and wounded in ten 

fewer days than Paul Revere IV, with enemy losses of killed 

and captured nearly 200 fewer. The enemy was adapting his 

tactics to mitigate the effects of U.S. firepower, and taking full 

advantage of the Cambodian safe zone to avoid battle when he 
47

wished. On the balance, however, General Peers believed that 

maintaining a strong forward defense was worth the effort, 

and resolved to fight along the border whenever necessary. 

Binh Dinh Province

The lull that descended over the western highlands at the 

beginning of 1967 permitted General Larsen to shift Colonel 

Shanahan’s 3d Brigade, 25th Infantry Division, down to the 

coastal lowlands of Binh Dinh Province to assist General 

Norton’s 1st Cavalry Division with a new operation called 

Pershing. Norton’s airmobile troopers had spent the last four 

months of 1966 securing the coastal lowlands and interior 

valleys of Phu My district with Operations Thayer I and II. 

Now the I Field Force commander wanted to push north onto 

the Bong Son Plain, a rich agrarian flatland that extended 

north twenty-five kilometers from the Lai Giang River to the 

hills at the southern edge of Quang Ngai Province, and west 

roughly ten kilometers from the South China Sea to the Hon 

Go Mountains. The Viet Cong controlled most of the 100,000 

farmers and fishermen who lived on the Bong Son Plain, as 

well as the 6,000 inhabitants of the An Lao Valley, which ran 

parallel to the Bong Son Plain on the western side of the Hon 

Go Mountains. General Norton’s mission was to destroy or 

drive away elements of the 3d PAVN Division that camped in 

the coastal hills overlooking the plain so South Vietnamese 

forces could begin pacifying the hamlets on the Bong Son 

Plain and relocating the civilians of the An Lao Valley to 

more secure locations. Once the rainy season ended in April 

or May, the 1st Cavalry Division commander hoped to extend 

Operation Pershing’s reach into the hills of southern Quang 

Ngai Province so he could disrupt the Viet Cong bases that 

supported the 3d PAVN Division on the north-central coast 

(Map 8).

In early January, Shanahan’s brigade settled into southern 

Phu My District so General Norton could consolidate his 1st 

and 2d Brigades farther north to prepare for Pershing. To 

support operations on the Bong Son Plain, Norton began accumulating supplies at Landing Zone English, five kilometers 

north of the Lai Giang River, located on Highway 1 next to the 

camp of the South Vietnamese 40th Regiment, 22d Infantry 

Division. Washed-out roads and poor flying weather slowed 
Map 8

1

1

514

514

506

22 PAVN

III

18 PAVN

III Dam Tra O

Dam Nuoc Ngot

SOUTH

CHINA

SEA

Song Lai Giang

Siem Giang

X

X

1–1 Cav

2–1 Cav

3–25(-)

1–1 Cav

LZ ENGLISH

LZ CRYSTAL

LZ HAMMOND

LZ TWO BITS

FSB PONY

FSB BIRD

18 Mar

6 Mar

11 Mar

PLAF Provincial HQ 19 Jan

8 Apr 18 Feb

6 Feb

7 Feb

19–21 Mar

PHU MY PLAIN

AN LAO VALLEY BONG SON PLAIN

HON GO MOUNTAINS

CAY GIEP MOUNTAINS

'THE CRESCENT'

NUI MIEU 

SUOI CA VALLEY

KIM SON VALLEY

DAMS

DAMS

Sa Huynh 

Tuy An 

Binh Hoa

Hoai Nhon

Hoai An

Phu My

Phu Cat

Bong Son

Hoa Tan

Hung Long An Lao Tam Quan

Q UA N G N G A I

BI N H D I N H

1ST CAVALRY DIVISION

OPERATIONAL THEATER

January–April 1967

Engagement

0

0 5 Kilometers

Miles 5

0 200 400 600 800 and Above

ELEVATION IN METERS
49

the buildup at English, delaying the start of the operation 

until the second week of February. 

Norton’s soldiers caught only sporadic glimpses of the enemy 

during the initial stage of Operation Pershing. The sudden 

appearance of four cavalry battalions and hundreds of helicopters 

on the southern Bong Son Plain convinced the 22d PAVN and 2d 

PLAF Regiments to head north to the comparative safety of Quang 

Ngai Province. The 1st Cavalry Division had driven the 3d PAVN 

Division out of the resource-rich district for the first time in the 

war, allowing the South Vietnamese to begin extending government control to a greater portion of the Bong Son Plain. 

While the 3d Division’s remaining unit, the 18th PAVN 

Regiment, continued to cling to its traditional sector in Phu 

My and Phu Cat Districts in central Binh Dinh Province on 6 

March, helicopter scouts from the 1st Cavalry Division discovered a battalion from the regiment concealed in a hamlet near 

the Tra O Marsh, sixteen kilometers southeast of Landing 

Zone English. Colonel Shanahan swept the area with elements 

from his 3d Brigade, 25th Infantry Division, killing eighty-two 

North Vietnamese soldiers before the enemy vanished into the 

Soldiers of the 1st Cavalry Division (Airmobile) await the second wave of combat helicopters 

during Operation Pershing. National Archives
50 

costal hills. Colonel Casey’s 2d Brigade joined the hunt around 

Tra O Marsh, but on 11 March Communist troops ambushed 

a company from the 1st Cavalry Division during a helicopter 

insertion, killing nineteen Americans and wounding twentyfive for an apparent loss of only ten men. As the twin fights 

demonstrated, the airmobile prowess of the 1st Cavalry Division 

made it easier to find enemy units, but did not guarantee that the 

fight would always be on American terms. 

The focus of Operation Pershing shifted north again on 

18 March when the sapper battalion from the 3d PAVN Division

attacked a South Vietnamese outpost at the small port of Sa Huynh 

on the Quang Ngai-Binh Dinh border. General Norton ordered 

Smith to scour the northern Bong Son Plain with his 1st Brigade. 

On the evening of 19 March, a U.S. infantry company found 

the 22d Regiment in the hamlet of Truong Son, eighteen kilometers north of Landing Zone English. Colonel Smith brought 

in additional units to surround the area while General Norton 

deployed most of Colonel Casey’s 2d Brigade to join the chase. 

Over the next three days U.S. units killed 120 North Vietnamese 

“Skytroopers” of the 1st Cavalry Division (Airmobile) dismount on a beach on the South 

China Sea during Operation Pershing. National Archives
51

soldiers while losing 34 themselves. The bulk of the 22d Regiment 

managed to escape into southern Quang Ngai Province. Norton 

resolved to pursue the battered 3d PAVN Division in April when 

drier weather would bring better flying conditions. 

Though the results were less than he had hoped, General 

Larsen still looked favorably on the I Field Force wet season 

campaign for the central coast. In Binh Dinh Province, Operations 

Thayer and Pershing had inflicted heavy losses on the 3d 

PAVN Division and driven it from the populated lowlands to the 

barren coastal hills where food and clean water were scarce. The 

withdrawal left the hamlet-based guerrillas and political cadre 

more vulnerable to allied sweeps. Indeed, the Hamlet Evaluation 

System reports submitted by the U.S. advisory detachment in 

Binh Dinh indicated that the percentage of the population living 

under government control had increased from 22 percent to 68 

percent between October 1966 and April 1967. Unfortunately, a 

large part of that increase had come through the forced or voluntary displacement of civilians. By the spring of 1967, nearly 20 

percent of Binh Dinh’s population, some 140,000 people, had 

moved from enemy-controlled villages to squalid refugee camps 

An artilleryman during Operation Pershing National Archives
52 

that the government had erected on the outskirts of regional 

towns, straining the ability of provincial administrators to care 

for their needs.

Farther down the coast in II Corps, the allies had also made 

important gains. In Phu Yen Province, the two South Korean 

infantry divisions had relieved the 1st Brigade, 4th Infantry 

Division, in the Tuy Hoa Basin, permitting Larsen to move it 

into the western highlands on a permanent basis. South Korean 

forces had also expanded their sector in Ninh Thuan Province, 

allowing Westmoreland to move the 1st Brigade, 101st Airborne 

Division, from the Phan Rang Basin to southern I Corps in late 

April. To the south in Binh Thuan Province, Task Force Byrd

had helped South Vietnamese forces establish a viable pacification program in the rice-growing basin around the provincial 

capital of Phan Thiet. 

Shielded by the half-dozen U.S. and South Korean brigades 

on the central coast, MACV’s logistical support system continued 

to grow. The U.S. Army Support Command at Cam Ranh Bay 

served as the principal supply center for all of the allied forces in 

southern II Corps, while the 54th General Support Group provided 

a smaller hub at Nha Trang in Khanh Hoa Province. Based at 

Cam Ranh Bay, the 35th Engineer Group (Construction) built all 

of the roads, structures, airfields, storage areas, and port facilities 

required by I Field Force in southern II Corps. The 45th Engineer 

Group (Construction) performed a similar role in northern II 

Corps from Tuy Hoa and Qui Nhon. The 16th Military Police 

Group worked with the logistical units in II Corps, performing a 

range of tasks including convoy protection, installation security, 

traffic control, and theft prevention. Operating from mountain 

peaks across II Corps, units from the 21st Signal Group helped 

coordinate the increasingly complex activities of I Field Force.

Task Force Oregon

By early 1967 it was clear to General Westmoreland that 

III Marine Amphibious Force needed additional combat power 

to hold the line in I Corps. MACV intelligence noted a steady 

buildup of North Vietnamese units, with eight regiments 

now hovering just above the Demilitarized Zone and two 

more to the west in Laos. The enemy had begun bombarding 

U.S. Marine outposts in northern Quang Tri Province with 

122-mm. rockets and 130-mm. guns, a significant escalation of 
53

firepower compared to the 82-mm. mortars the Communists 

had used in the past. North Vietnamese logisticians had also 

turned the A Shau Valley in western Thua Thien Province 

into a major depot, shortening the time and effort it took 

to get supplies to troops in the coastal lowlands of I Corps. 

Consequently, Westmoreland decided to compose a provisional 

Army formation using brigades borrowed from I and II Field 

Force to defend southern I Corps, allowing the commander 

of III Marine Amphibious Force, Lt. Gen. Lewis W. Walt, to 

concentrate his 1st and 3d Marine Divisions exclusively in the 

northern part of I Corps (Map 9). 

Southern I Corps—the lower portion of Quang Nam 

Province as well as Quang Ngai and Quang Tin Provinces—had 

been a bastion of Communist support going back to the Indochina 

War. A majority of the rural population had lived under de facto 

Communist control for almost two decades. Government forces 

stayed close to the regional towns and Highway 1, the main 

north-south road through the narrow coastal lowlands. The 

interior mountains that covered some 80 percent of southern I 

Corps contained a sprinkling of Montagnard communities and 

six Special Forces camps. A Communist trail network moved 

troops and supplies through the mountains from Base Area 614 

in Laos through the Do Xa War Zone in south-central Quang 

Ngai Province, a waypoint that contained the Military Region 5

headquarters, and then to forward bases in the coastal hills of 

southern I Corps. Both the 2d and 3d PAVN Divisions as well as a 

dozen Viet Cong infantry battalions relied on this network for the 

supplies and equipment they needed to fight, except food which 

they procured locally. 

In the autumn of 1966, MACV developed a plan to disrupt 

the enemy camp system in I Corps with a series of airmobile raids spearheaded by the 1st Cavalry Division. Dubbed 

Operation York, the plan depended on the allies achieving 

enough stability in II Corps that Westmoreland could detach 

the 1st Cavalry Division from I Field Force without jeopardizing 

the region. Beginning with the Do Xa War Zone in Quang Ngai 

Province, the 1st Cavalry Division would leapfrog up the chain 

of enemy bases that dotted the interior mountains of I Corps, 

using its fleet of helicopters to reach those remote areas which 

III Marine Amphibious Force, overextended as it was, had not 

been able to strike. 
54 

In the spring of 1967, however, the 1st Cavalry Division was 

still needed in Binh Dinh Province, so Westmoreland authorized the formation of a provisional force to hold the line until 

Operation York could be organized and logistical upgrades put 

in place to support an airmobile division in I Corps. On 6 April, 

the MACV commander formed Task Force Oregon, putting it 

under the command of his chief of staff, Maj. Gen. William B. 

Rosson, and naming it after Rosson’s home state. Westmoreland 

assigned three brigades to the force: the 1st Brigade, 101st Airborne 

Division, then on the southern coast of II Corps; the 3d Brigade, 

Map 9

ARVN

XXX

I

XXX

III MAF

1 Mar

X X

3 Mar

X X

23

X X

OPERATION BENTON 13–29 Aug 67

OPERATION WALLOWA 4 Oct 67–11 Nov 68

OPERATION WHEELER 11 Sep–25 Nov 67

OPERATION HOOD RIVER 2–13 Aug 67

OPERATION LEJEUNE 7–22 Apr 67

DA NANG

HUE

CHU LAI

LZ COLT

LZ BALDY

BA TO

BRONCO

GIA VUC

BASE AREA 610

BASE AREA 611

BASE AREA 614

BASE AREA

607

BASE AREA

117 DO XA 

WAR ZONE BASE AREA 121

B1 FRONT

B4 FRONT

B5 FRONT

B3 FRONT

II CTZ

SOUTH CHINA SEA

1

9

1

1

14

DEMARCATION LINE

Quang Tri

Con Thien

Khe

 Sanh

A Shau

Dong Ha

Hoi An

Que Son

Tam Ky

Quang Ngai

QUANG TRI

THUA THIEN

QUANG NAM

QUANG TIN

QUANG NGAI

KONTUM

BINH DINH

NORTH VIETNAM

LAOS

CAMBODIA

Corps Tactical Zone Boundary

Communist Front Boundary

Engagement

1967–1968

I CORPS TACTICAL ZONE

0 50 Miles

0 50 Kilometers
55

25th Infantry Division, presently serving with the 1st Cavalry 

Division in Binh Dinh Province; and the 196th Infantry Brigade, 

currently operating with the 25th Infantry Division in Tay Ninh 

Province. He directed those brigades to deploy to southern I 

Corps by 1 May, with Shanahan’s 3d Brigade going to Duc Pho on 

the southeastern coast of Quang Ngai Province, and the other two 

brigades to Chu Lai, an air base complex on the southern coast of 

Quang Tin Province where Rosson would establish his headquarters. Task Force Oregon would receive its logistical support from 

III Marine Amphibious Force, most of it delivered via Highway 1 

from the port of Da Nang. Rosson reported to General Walt, but 

the Marine commander gave his Army subordinate a wide degree 

of flexibility in operational matters (Map 10). 

The air base at Chu Lai offered all of the facilities needed by 

Brig. Gen. Richard T. Knowles and the 196th Infantry Brigade 

when they arrived from III Corps in mid-April. In addition to 

his three infantry battalions, Knowles also took control over a 

battalion from Shanahan’s 3d Brigade, 25th Infantry Division, 

and a squadron from the 11th Armored Cavalry. 

Unlike Chu Lai, the small outpost at Duc Pho needed significant upgrades to accommodate a full brigade. Westmoreland 

ordered the new commander of the 1st Cavalry Division, Maj. 

Gen. John J. Tolson, to send a task force to Duc Pho in early April 

to pave the way for Colonel Shanahan’s 3d Brigade, 25th Infantry 

Division. On 7 April Tolson commenced Operation Lejeune, 

sending two cavalry battalions and his 2d Brigade headquarters 

to relieve the Marine units at Duc Pho, which then headed north 

to Quang Nam Province. Meanwhile, the 8th Engineer Battalion, 

1st Cavalry Division, and the 39th Engineer Battalion (Combat) 

from I Field Force turned the airfield into an all-weather runway 

capable of handling C–130 transport aircraft, and established 

an over-the-beach logistical facility named Razorback on the 

coast to the east. The 1st Cavalry Division completed its work in 

the second half of April, returning to Binh Dinh Province and 

making way for Colonel Shanahan’s 3d Brigade to move into its 

new base camp at Duc Pho, Landing Zone Bronco. 

As the first two brigades of Task Force Oregon settled 

into their new homes, General Rosson received intelligence that 

the 22d PAVN Regiment and the headquarters of the 3d PAVN 

Division had moved from Binh Dinh Province into the hills of 

southern Quang Ngai Province to link up with the division’s 2d 
Map 10

TF OREGON

X X

2 11

I I

1 14

I I

196

X

1 101

3 25

X

X

Song Tra Bong

Song Tra Khuc

Song Ve

Song Re

Song Tra Cau

SOUTH

CHINA

SEA

BASE AREA 121

BASE AREA 122

BASE AREA 123

BASE AREA 124

mid Jun

28–29 May 22–30 Apr

20 Aug

8 Aug

18 May

13 May

22 May

mid Jul

9 Jun

QUANG NGAI

FSB DRAGON

FSB LIZ

CARENTAN

RAZORBACK

CHU LAI

LZ BRONCO

BA TO Special Forces Camp

GIA VUC

Special Forces Camp

MINH LONG Special Forces Camp

HA THANH

Special Forces Camp

TRA BONG

Special Forces Camp

1

1

1

1

5B

518

529

516

515

BATANGAN PENINSULA

Ky Khuong

An Tay

Binh Son

Son Tinh

Son Ha

Ba To

Gia Vuc

Mo Duc

Ba Ria

Duc Pho

Nghia Hanh

An Hai

QUANG NGAI

Q UA N G T I N

Q UA N G N G A I

KO N T U M

Q UA N G N G A I

TASK FORCE OREGON

OPERATIONAL THEATER

April–August 1967

Engagement

0

0 5 Kilometers

Miles 5

0 200 500 800 and Above

ELEVATION IN METERS
57

PLAF Regiment. Rosson also learned that the 1st PLAF Regiment

of the 2d PAVN Division had shifted south from Quang Tin 

Province into Quang Ngai Province. This unusual concentration 

raised the possibility that the enemy intended to overrun either 

the Ba To Special Forces camp, located in the Song Ve Valley 

twenty-five kilometers west of Duc Pho, or the Minh Long Special 

Forces camp twenty-two kilometers to its north. The hills that 

surrounded those camps contained a network of enemy installations that collectively served as the main depot and distribution 

point for North Vietnamese supplies coming from Base Area 614 

in Laos. If the Communists overran one or both Special Forces 

camps, the allies would find it much harder to monitor those hills 

and therefore anticipate enemy offensives in southern Quang 

Ngai Province.

At General Rosson’s request, General Westmoreland agreed 

to move the 1st Brigade, 101st Airborne Division, from southern 

II Corps to Duc Pho immediately, giving Task Force Oregon its 

third brigade in early May rather than at the end of the month. 

As a temporary expedient, Westmoreland also shifted the I 

Members of the 1st Cavalry Division (Airmobile) landing on a hilltop during Operation Lejeune

in 1967. National Archives
58 

Field Force boundary north to include Quang Ngai Province in 

the event that Task Force Oregon needed reinforcements from 

Tolson’s 1st Cavalry Division. 

Over the next few weeks, the pair of infantry battalions 

from the 3d Brigade, 25th Infantry Division, operating under 

Colonel Shanahan’s control saw the most action, skirmishing in 

the lowlands around Duc Pho and Liz, a firebase that Shanahan 

established ten kilometers northwest of Bronco to extend the 

range of his artillery coverage. His troops mostly encountered 

Viet Cong local force units, but on 22 May the 1st Battalion, 35th 

Infantry, 3d Brigade, 25th Infantry Division, trapped a battalion 

from the 22d PAVN Regiment in a hamlet southeast of Bronco. 

The Americans killed at least seventy North Vietnamese troops, 

putting that enemy battalion out of action for the next six months. 

On 29 May, Shanahan’s brigade cornered another enemy battalion, 

this one from the 1st PLAF Regiment, just west of Firebase Liz, 

killing eighty-one Viet Cong soldiers and preempting an attack 

on the post. 

As the 3d Brigade, 25th Infantry Division, swept the 

lowlands, the 1st Brigade, 101st Airborne Division, went hunting 

for the North Vietnamese units that threatened the Ba To and 

Minh Long Special Forces camps. After the airborne brigade had 

landed at Razorback beach in early May, its commander, Brig. 

Gen. Salve H. Matheson, had established a camp near Duc Pho 

known as Carentan. He had then sent two of his battalions into 

the forested hills overlooking the Ve and Tra Cau River Valleys, 

holding his third in reserve. His paratroopers had clashed with 

company-sized enemy units throughout May and into June, 

killing over 400 Communists and razing several Viet Cong 

camps. When Colonel Matheson received intelligence that the 

enemy planned to overrun the Mo Duc district headquarters, ten 

kilometers north of Liz, he established a new firebase just west of 

town called Dragon. Thwarted, the enemy shifted his focus to 

the south, hitting Bronco on 23 June with a mortar barrage that 

killed three Americans and wounded fifty-one more. 

Despite the attack on its main camp, the 3d Brigade, 25th 

Infantry Division, now under the command of Col. George E. 

Wear, continued to get the best of the enemy in Duc Pho District. 

Colonel Wear’s men became increasingly proficient at finding 

the concealed fighting pits and tunnels where Viet Cong soldiers 

hid themselves, and more savvy about avoiding the booby traps 
59

that seemed to be everywhere. As June passed into July, contact 

dwindled in the hills and lowlands of southern Quang Ngai 

Province. South Vietnamese forces took advantage of the better 

security situation to relocate 7,000 civilians from the Ve and Tra 

Cau River Valleys to refugee camps on the coast, denying the 

enemy the food and labor formerly provided by those farmers.

The 196th Infantry Brigade and the squadron from the 11th 

Armored Cavalry saw relatively little action around Chu Lai in 

May and June. On 1 June, the command of Task Force Oregon

passed from General Rosson to Maj. Gen. Richard Knowles, the 

former commander of the 196th Brigade who now received his 

second star. Toward the end of July, Knowles received intelligence that the 2d PAVN Division was preparing to attack Quang 

Ngai City with its 1st PLAF and 21st PAVN Regiments before the 

government held elections to choose delegates for the National 

Assembly, an important step on South Vietnam’s path toward 

becoming a constitutional democracy. On 2 August, U.S., South 

Korean, and South Vietnamese units launched a combined sweep 

through the foothills west of Quang Ngai City and south of the Tra 

Khuc River where they thought the enemy was located. Operation 

Hood River used the 1st Brigade, 101st Airborne Division, and 

elements of the 196th Brigade as blocking forces while units from 

the South Korean 2d Marine Brigade, the South Vietnamese 2d 

Infantry Division, and two South Vietnamese ranger battalions 

spearheaded the search. The results were disappointing. Possibly 

tipped off by spies, the enemy proved hard to find; between 2 and 

13 August, the allies killed only 166 Communist soldiers, while 

losing 21 killed and 133 wounded themselves, many of those casualties coming from mines and booby traps. Even so, Operation 

Hood River ensured that the 2d PAVN Division posed no immediate threat to Quang Ngai City. 

As Hood River began winding down, General Knowles shifted 

units to meet a new threat in Base Area 117 in Quang Tin Province 

west of Chu Lai. Intelligence reported that the 21st PAVN Regiment 

from the 2d Division and a Viet Cong local force battalion had moved 

into Base Area 117 in the foothills southwest of Tam Ky to protect 

a North Vietnamese rocket artillery unit that intended to bombard 

Tam Ky and other towns on the coast to discourage voter turnout for 

the September elections. On 12 August a large enemy force attacked 

a South Vietnamese ranger battalion just north of those foothills, 

confirming the presence of Communist units. The next day, General 
60 

Knowles began Operation Benton by air assaulting two battalions 

from Matheson’s 1st Brigade, 101st Airborne Division, into the area 

and placing two battalions from the 196th Brigade as a blocking 

force between Base Area 117 and Tam Ky. The airborne battalions 

skirmished with elements of the 21st PAVN Regiment but found it 

impossible to locate the main enemy body in the dense, junglecovered hills. Knowles committed the third paratrooper battalion on 

15 August but the results continued to be meager. When Task Force 

Oregon ended Operation Benton on 29 August, its soldiers had 

killed 303 enemy soldiers and captured a modest amount of weapons, 

ammunition, and other supplies. U.S. losses totaled 45 killed and 326 

wounded, plus 5 helicopters shot down. 

As the elections neared in early September, the 2d PAVN 

Division moved north into the Que Son Valley, a fertile and densely 

populated basin that straddled the border between Quang Tin and 

Quang Nam Provinces. Not only did the valley offer the enemy a 

chance to replenish his food stores, it was also less well-defended 

than the areas to the south patrolled by Task Force Oregon. The 

III Marine Amphibious Force commander, General Walt, was in 

“Duster” 40-mm. at the perimeter of Landing Zone Uplift, overlooking Highway 1 in Augu

1967.

National Archives
61

the process of shifting his 1st Marine Division farther north to deal 

with the growing threat in Quang Tri and Thua Thien Provinces. 

Only two battalions from the 5th Marines remained in the Que Son 

Valley, and unlike similar Army formations, the marines possessed 

relatively few helicopters. 

The enemy took advantage of the thinning U.S. presence 

in southern Quang Nam. At the end of August the Communists 

attacked and partly overran the provincial capital of Hoi An 

and two district towns. Then, on 4 September, they attacked 

a Marine company in the Que Son Valley, drawing in and 

pinning down four additional Marine companies while three 

local force battalions converged on Tam Ky near the coast. 

South Vietnamese units and U.S. air strikes repulsed the Viet 

Cong assault force before it reached the city, killing over 200 

enemy soldiers, but the marines in the Que Son Valley paid 

a fearful price. Almost 100 Americans died in the three-day 

battle that also claimed the lives of nearly 400 enemy soldiers 

from the 1st PLAF Regiment. 

Generals Westmoreland and Walt agreed that III Marine 

Amphibious Force needed more troops to hold the Que Son National Archives

Company C, 2d Battalion, 34th Armor, with Task Force Oregon near Duc Pho in June 1967
62 

Valley. Enemy pressure was also starting to build on the 3d Marine 

Division positions south of the Demilitarized Zone, particularly 

the battalion-sized firebases that Marine and Navy engineers had 

built in the eastern lowlands to anchor the Strong Point Obstacle 

System, the anti-infiltration barrier more commonly known as the 

McNamara Line. Several of those strong points lay within range 

of artillery firing from North Vietnam. The outpost at Con Thien 

was particularly hard hit, receiving more than 1,000 rounds of 

artillery, rocket, and mortar fire on 25 September alone. General 

Walt also needed to ensure that Highway 1, the main supply route 

between his logistical hub at Da Nang and his northernmost 

bases, remained secure at all times. With nothing to spare, he 

agreed that it would be up to the Army to take care of the Que Son 

Valley and the rest of southern I Corps. 

In recognition of that fact, General Westmoreland received 

approval from the Army to transform Task Force Oregon into a 

full division-sized formation with its own organic units and a more 

robust logistical support system. On 25 September, the task force 

became the 23d Infantry Division (Americal), commanded by Maj. 

Gen. Samuel W. Koster. For the moment, the division would consist 

of the 196th Infantry Brigade, the 3d Brigade, 4th Infantry Division, 

and the 1st Brigade, 101st Airborne Division. In November and 

December, the latter two brigades would return to their parent divisions and a pair of newly activated units, the 11th and 198th Infantry 

Brigades, would join the Americal. The division’s reconnaissance 

element, the 1st Squadron, 1st Cavalry, had already arrived at Chu 

Lai in August. The cavalry element of Task Force Oregon, the 2d 

Squadron, 11th Armored Cavalry, would continue to operate from 

Chu Lai until October when it would return to III Corps. 

When General Koster took command of the Americal 

Division, General Matheson’s 1st Brigade, 101st Airborne Division, 

was hunting for the 2d PAVN Division in the lower Que Son Valley 

west of Tam Ky. Matheson believed that the enemy had pulled back 

into the mountains to regroup near the abandoned district capital 

of Hiep Duc. He therefore planned Operation Wheeler as a multibattalion encirclement to trap and then destroy a major element of 

the North Vietnamese division. After two of his battalions established blocking positions to the west and south of the town, and 

U.S. Marine and South Vietnamese units occupied high ground to 

the north overlooking Route 534 to cordon off the area, Matheson 

inserted one infantry battalion to drive from the east to Hiep Duc 
63

on 26 September. Despite resistance for more than a week, all three 

battalions advanced and tightened the encirclement. 

As the weather deteriorated and gave way to heavy downpours, the enemy continued to evade, but occasionally infiltrated 

behind U.S. units. Koster reinforced the airborne brigade with 

an additional battalion on 4 October. The Americans encountered stiffer opposition when at midnight the enemy attacked 

an airborne company. After the enemy overran one platoon, the 

company repelled the assault. Another enemy force attacked a 

nearby firebase defended by South Vietnamese militia. Although 

the artillerymen managed to repel the attack, the weather favored 

the enemy as rainstorms hampered movement, caused logistical 

problems, and limited air support.

While the paratroopers conducted Operation Wheeler, 

Westmoreland decided to reinforce Koster with Col. James O. 

McKenna’s 3d Brigade, 1st Cavalry Division, so the Americal 

Division could cover the upper part of the Que Son Valley. On 

3 October, McKenna launched Operation Wallowa, with his 

command post and one battalion at Landing Zone Baldy, thirty 

kilometers northwest of Tam Ky, a second battalion on Hill 23 

at a firebase named Landing Zone Colt, and the third at a post 

formerly occupied by marines on a hill near Que Son. McKenna 

initially punished scattered enemy units moving in the area, but 

before the Americans had completed their defenses, the enemy 

infiltrated Colt’s perimeter early on 10 October, causing considerable damage.

Guided by captured documents that indicated the presence 

of a North Vietnamese regiment just west of Baldy, McKenna 

retaliated on the morning of 20 October. Reinforced by the 1st 

Squadron, 1st Cavalry, and artillery and air support, the brigade 

inflicted lopsided casualties in a number of small fights. Seven 

days later, the Americans beat back a fierce North Vietnamese 

counterattack launched to cover the withdrawal of the rest of 

their forces. Although the Americans failed to destroy the enemy 

regiment, they succeeded in keeping it from the populated areas 

and sources of forage. Most of the enemy’s casualties proved to 

be North Vietnamese regulars, not local guerrillas, and captured 

documents confirmed that the Americans had badly hurt the 

2d PAVN Division. When October ended, Task Force Oregon 

(the Americal Division) had enjoyed some tactical successes, 

but had not achieved the ambitious results Westmoreland had 
64 

hoped. American soldiers inflicted about 1,400 casualties, divided 

equally between North Vietnamese and Viet Cong main forces, 

local forces, and guerrillas.

The Highlands Again

During the rainy season, the B3 Front had replaced its 

losses, and by mid-summer 1967 it had seven regiments in 

the Central Highlands of II Corps. Three were part of the 1st 

PAVN Division located in Cambodia, while the others operated 

independently with one each in Darlac and Pleiku and two 

in Kontum Provinces. The Communists intended to operate 

as before, drawing U.S. units away from the populated coast 

into the rugged border regions to inflict heavy losses on them. 

Learning of the B3 Front buildup from intelligence reports, 

General Peers decided to send his 4th Infantry Division into 

a new border campaign called Operation Francis Marion

on 6 April, orienting his 1st Brigade around Duc Co to shield 

the western approach to Pleiku City and his 2d Brigade farther 

south in the area around Plei Me.

A mechanized battalion from Peer’s 2d Brigade gained 

the first major contact of Francis Marion on 30 April when it 

ambushed a North Vietnamese force north of Plei Me. The enemy 

attempted to break contact, but the Americans pursued them to 

A Special Forces–trained Montagnard strike force. National Archives
65

a fortified camp. As U.S. tanks and armored personnel carriers 

overran part of the base, the North Vietnamese launched a 

desperate counterattack that failed to stop the armored vehicles. 

A day later on 1 May, a company from the 1st Brigade, 4th 

Infantry Division, repulsed a battalion-sized attack near Duc 

Co. Prisoners and other intelligence gathered as a result of the 

battles indicated that the B3 Front was moving a division-sized 

force into southwestern Pleiku Province for a major offensive 

sometime in June.

Peers initiated preemptive attacks in mid-May, having 

infantry check the border following B–52 strikes. He found 

little evidence of the enemy until 18 May when the sighting of 

a single enemy soldier precipitated a nine-day battle. Unknown 

to the Americans, the enemy had sent tracking parties to locate 

isolated platoon- and company-sized positions to attack with 

battalion-sized units. During the course of the first encounter, 

the North Vietnamese overran a platoon of the 1st Battalion, 

8th Infantry, executing their captives before relief arrived. The 

enemy then made three unsuccessful assaults over a two-hour 

period against the Americans who had occupied one of his base 

camps for a night defensive position. The North Vietnamese 

withdrew and remained quiet for the next three days until 21 

May, when a battalion advanced behind a mortar barrage in 

an unsuccessful attack against two U.S. companies of the 3d 

Battalion, 12th Infantry. 

M48 tank National Archives
66 

Three days later, two companies of the 3d Battalion, 12th 

Infantry, went to a clearing to await helicopter evacuation while 

a third company began digging in on nearby high ground. The 

North Vietnamese attacked the troops waiting for airlift, but 

broke off the assault when the soldiers of the remaining company 

left their fighting positions and went to their comrades’ aid. 

Two companies from 3d Battalion, 8th Infantry, tried to link 

up with the beleaguered force when a ground attack hit them 

in the lower Ia Tchar Valley. The men from the 8th Infantry 

rebuffed repeated assaults until reinforcements arrived. In the 

five battles fought over the nine-day period in May, U.S. forces 

had performed well, inflicting disproportionate casualties under 

difficult circumstances.

After the North Vietnamese attacked government installations at Kontum City and Tan Canh and the Special Forces camp 

at Dak To with mortars and rockets on 17 June, General Peers 

ordered the commander of the 173d Airborne Brigade, Brig. Gen. 

John R. Deane, to send two battalions along with supporting 

armor and artillery into the area on Operation Greeley. Five days 

later, on 22 June, while conducting a search and destroy mission 

in the steep, jungle-covered mountains five kilometers south of 

Dak To, a company of paratroopers engaged an enemy battalion 

heading back to Laos. In the violent fight that followed, the 

company became separated into two groups and suffered heavy 

casualties before reinforcements forced the enemy to withdraw 

and helicopters extracted the battered paratroopers.

Having identified at least one regiment of the 1st PAVN 

Division in the area, I Field Force Commander General Larsen 

sent the 1st Brigade, 1st Cavalry Division, to Dak To and the 

two-battalion 1st Airborne Task Force of the South Vietnamese 

Army to Kontum as reinforcements for the 4th Division. As one 

battalion each from the 1st Cavalry Division and 173d Airborne 

Brigade moved to block routes into Laos, the paratroopers who 

had fought the previous day returned to the battle site, finding 

that the enemy had executed those Americans who had been 

wounded and captured. 

When Larsen’s sweep came up empty, he returned the 1st 

Brigade, 1st Cavalry Division, to Binh Dinh Province until a 

new threat emerged. In early August, North Vietnamese units 

converged on the Dak Seang Special Forces camp in the far 

northwestern corner of Kontum Province, but the II Corps 
67

Commander General Vinh Loc took the lead this time sending 

an infantry regiment and an airborne task force to defend the 

outpost. Backed by U.S. air support, the South Vietnamese 

troops inflicted heavy casualties on the North Vietnamese and 

drove them back into Laos.

Operation Francis Marion came to a close in mid-October 

having yielded mixed results. The allied forces claimed to have 

killed 1,000 enemy troops at the cost of 300 U.S. and 100 South 

Vietnamese dead, resulting in a relatively high ratio of enemy-tofriendly killed. The border defense operation had prevented the B3 

Front from overrunning any of the allied border positions, but it 

had also diverted I Field Force units from missions on the central 

coast. As the dry season approached in the western highlands, 

General Peers expected the enemy to renew his attacks, once 

again testing the ability of the 4th Infantry Division to protect 

300 kilometers of rugged territory. 

Summer in the II Corps Lowlands

Down in the coastal lowlands of Binh Dinh and Phu Yen 

Provinces, the 1st Cavalry Division and the 173d Airborne 

Brigade saw few signs of the 3d PAVN Division and the 95th PAVN 

Regiment between May and July 1967 as the enemy spent the first 

half of the dry season hiding in the mountains and building 

up supplies for future offensives. General Tolson’s 1st and 2d 

Brigades continued to patrol the Bong Son and Phu My Plains 

while his 3d Brigade extended Operation Pershing into the Sang 

Mountains and Nuoc Dinh Valley on the border between Binh 

Dinh and Quang Ngai Provinces. Although the soldiers uncovered a number of bases and engaged caretaker units, the enemy 

again avoided substantial contact.

General Tolson sent Colonel McKenna’s 3d Brigade, back 

under 1st Cavalry Division control, to the Song Be Valley in 

Quang Ngai Province on 7 August. Leapfrogging infantry battalions and artillery firebases south, the brigade encountered little 

resistance until the morning of 9 August. After one company air 

assaulted into a landing zone fifteen kilometers north of Gia Vuc, 

North Vietnamese troops opened fire and swarmed its perimeter. 

Unable to destroy the Americans after four hours of fighting, 

the enemy broke contact and withdrew. The brigade continued 

searching northward but found little evidence of enemy’s presence 

until it ended the operation on 21 August and returned to the An 
68 

Lo Valley, at which time Tolson detached two of the battalions to 

reinforce the other brigades on the coastal plain.

After an enemy battalion unsuccessfully attacked one of its 

companies just east of Landing Zone English on 22 August, 1st 

Cavalry Division leaders anticipated an attack on the base itself. 

Instead, the enemy attacked the division’s forward command post 

at midnight on 25 August. Concentrated defensive fire disrupted 

the attack and upset North Vietnamese plans to interfere with the 

South Vietnamese elections in Binh Dinh Province. As the 1st 

Cavalry Division ended Operation Pershing, which lasted from 

February to October 1967, it had killed 3,900 and captured more 

than 2,100 enemy troops. U.S. casualties numbered 498 dead and 

2,361 wounded. 

The Wet Season in III Corps

During the first half of 1967, the 1st Infantry Division had 

successfully kept Communist regulars away from the most populated areas of northern III Corps, but II Field Force Commander 

General Palmer expected the enemy to try something with the 

onset of the rainy season. He directed the 1st Division to have its 

2d Brigade continue to support pacification efforts in the vicinity 

of Di An, Binh Duong Province, as the 1st and 3d Brigades 

provided a shield against the 9th PLAF Division, which at the time 

was residing in a major base area called War Zone D, northeast of 

Saigon (Map 11). 

Code named Operation Billings, General Hay had the 

1st Division begin a spoiling attack north of Phuoc Vinh, a 

district capital in Binh Duong Province, on 12 June. The lack 

of contact seemed to indicate that the Viet Cong had retreated 

farther north to a large clearing designated as Landing Zone 

X-Ray. Anticipating that the enemy would be waiting to oppose 

an airmobile insertion, Hay directed Colonel Marks to march 

his 3d Brigade overland to secure X-Ray. The walking artillery 

barrage that preceded his leading units on 17 June unfortunately 

telegraphed the plan. 

Soon after the two battalions formed a perimeter at Landing 

Zone X-Ray, a patrol reported movement from the northwest. 

At 1300 a Viet Cong force estimated at two battalions penetrated 

the perimeter from the north and northwest. With artillery 

and helicopter gunship support, the defenders managed to turn 

back repeated assaults when a second wave struck the southeast 
69

perimeter. Despite heavy losses, the enemy overran one platoon 

before air strikes stabilized the situation at 1345. The enemy then 

withdrew under the cover of a twenty-minute mortar barrage. The 

division’s reaction force arrived to reinforce the perimeter just as 

the fight ended. 

Map 11

OPERATION BILLINGS 12–26 Jun

OPERATION

DIAMOND HEAD 11 Jul–7 Dec OPERATION

AKRON

9–29 Jun

BIEN HOA

CU CHI

TAY NINH DAU TIENG WEST

DI AN LONG BINH

PHUOC VINH

LZ X-RAY

QUAN LOI

TONG LE CHON

BEAR CAT

XUAN LOC

TUC TRUNG

BLACKHORSE

VUNG TAU

IV CTZ

II CTZ

 CAPITAL MILITARY DISTRICT

WAR ZONE C

HAT DICH

WAR ZONE D

SOUTH CHINA SEA

14

20

15

13

1

1

4

4

4

4

22

PHUOC TUY

BINH TUY

BINH

THUAN

LONG KHANH

PHUOC LONG

LONG AN

GO CONG

KIEN HOA

DINH TUONG

GIA DINH

BIEN HOA

QUANG DUC

LAM DONG

BINH

LONG

VINH BINH

VINH LONG

HAU NGHIA

KIEN TUONG

BINH DUONG

TAY NINH

An Loc

Loc Ninh

SAIGON

CAMBODIA

Corps Tactical Zone Boundary

Engagement

1967

III CORPS TACTICAL ZONE

0 50 Miles

0 50 Kilometers
70 

Patrols sent out the next morning and for several days 

thereafter found many enemy bodies. To continue to punish the 

retreating regiment, Hay placed heavy supporting fire, including 

B–52 strikes, on likely withdrawal routes and established blocking 

positions to the east and northeast of X-Ray. The enemy, however, 

remained elusive. In an effort to cover the battered regiment’s 

withdraw, General Thanh ordered elements of the 7th PAVN 

Division to conduct diversionary attacks on An Loc, capital of 

Binh Long Province, and the 1st Division’s forward base at Quan 

Loi, while his main attack seized the hamlet of Xa Tan Hung, five 

kilometers southeast of Quan Loi. 

Without conducting their usually thorough reconnaissance, North Vietnamese troops began leaving their assembly 

areas after dark on 10 July. The 7th Division lost the element of 

surprise when U.S. soldiers on the Quan Loi perimeter spotted 

movement just after midnight and opened fire. Although enemy 

sappers had already penetrated the base’s defensive wire and 

struck an artillery position when the fighting erupted, they failed 

to cut paths through the barriers that would have better enabled 

the assault forces to reinforce them. U.S. reaction forces killed 

or ejected all the sappers after two hours of fighting. Meanwhile, 

the attack on An Loc fizzled.

The diversion at Quan Loi had begun before the regiment 

making the main effort against Xa Tam Hung had reached its 

assault positions. Artillery illumination rounds from the nearby 

battle revealed the presence of the lead battalion as it moved 

through a grove of rubber trees, alerting the company of South 

Vietnamese soldiers defending the objective. Having lost communication with his headquarters, and fearing he would become 

a target for American artillery fire if he delayed, the enemy 

battalion commander immediately launched the attack without 

waiting for the follow-on forces. The North Vietnamese mortar 

preparation missed the defenders and fell instead on the village, 

causing many civilian casualties. The South Vietnamese company 

stubbornly defended its position, and as the battle at Quan Loi 

ended, U.S. artillery and gunships came to their support. The rest 

of the enemy force arrived and attacked piecemeal with disastrous 

results. As they retreated at dawn, North Vietnamese stragglers 

committed numerous atrocities against local inhabitants.

Throughout the summer, Communist forces conducted 

sporadic attacks, including artillery bombardments, on popu-
71

lated areas that killed many more civilians. This activity culminated in an attack by a Viet Cong regiment on the Tong Le 

Chon Special Forces camp shortly after midnight on 7 August. 

Before the defenders stopped the assault with the assistance 

of artillery and gunships, the Communists penetrated the 

southern perimeter and captured and executed a number of 

CIDG soldiers. 

During the first half of 1967, Philippine and South 

Vietnamese troops had used the relative quiet following 

Operations Attleboro, Cedar Falls, and Junction City

to redouble their pacification efforts in dozens of contested 

hamlets throughout Tay Ninh and Binh Duong Provinces. 

These activities came under renewed stress, however, once the 

7th PAVN Division had recovered enough from its earlier losses 

to return to the field. In late spring and early summer, Col. 

Kenneth E. Buell’s 3d Brigade, 25th Infantry Division, noticed 

increased hostile activity. When captured documents and 

prisoner interrogations indicated a North Vietnamese interest 

in the brigade’s base at Dau Tieng, Buell planned Operation 

Diamond Head.

On 11 July, the brigade’s units along with South Vietnamese 

Regional Forces made several sweeps toward the Cambodian 

border, but found no enemy concentrations or supply caches. That 

night, however, Viet Cong and North Vietnamese troops of the 

7th Division attacked government outposts between Tay Ninh 

West and Dau Tieng, overrunning one of them. The brigade’s 

battalions remained busy responding to sporadic infantry, rocket, 

and mortar attacks, but the foe avoided contact and dispersed 

before being brought to battle. 

The 25th Infantry Division’s 1st Brigade had similar experiences around Cu Chi in Hau Nghia Province. Col. Doniphan 

Carter had his 1st Brigade conduct numerous cordon, search, 

and civilian removal operations in conjunction with the South 

Vietnamese Army, turning the area around Phu Hoa village, 

fifteen kilometers northeast of Cu Chi, into a free-fire zone. In 

spite of several defeats, enemy forces usually escaped annihilation, and continued their rocket and mortar attacks on civilian 

areas. For the rest of the summer, the 25th Division and the 199th 

Brigade continued to search suspected enemy locations. With few 

exceptions, these maneuvers produced only fleeting contact with 

the enemy. 
72 

East of Saigon, the 9th Infantry Division’s new commander, 

Maj. Gen. George C. O’Connor, initiated a search and destroy 

mission that June against the 5th Division’s traditional staging 

area, a forested region in southeastern Bien Hoa Province known 

as the Hat Dich. From this sanctuary, enemy forces were within 

easy striking distance of Highway 1 to the north and Highway 15 

to the west, the two principal allied lines of communications in 

eastern III Corps. Operation Akron began on 9 June when the 

division’s 1st Brigade entered the western side of the Hat Dich, 

its plow-equipped engineers ready to destroy Viet Cong fortifications, while a squadron from the 11th Armored Cavalry and a 

South Vietnamese ranger battalion entered the eastern side of the 

Hat Dich. 

U.S. units involved in the operation rested in nighttime 

laagers, and at 0100 on 19 June the enemy struck one of these 

positions. The defenders—an armored cavalry troop, a battery 

of self-propelled 155-mm. howitzers, and a squadron headquarters—responded with their own firepower supported by helicopter 

gunships and artillery. The next morning the attackers evaded the 

pursuing Americans.

About a week later, the commander of the South Vietnamese 

18th Division, Brig. Gen. Do Ke Giai, sent a ranger battalion to 

investigate information given by defectors that a Communist 

battalion was located ten kilometers northwest of Tuc Trung, 

Long Khanh Province. Late on the afternoon of 27 June the 

rangers discovered a recently abandoned camp, which was 

actually a well-prepared ambush. After suffering many casualties, 

the rangers scattered to the east. A task force with two cavalry 

troops and two artillery batteries from the 11th Armored Cavalry 

went to help, but arrived too late and found only corpses and the 

detritus of battle. At the same time, a South Vietnamese battalion 

linked up with surviving rangers and renewed the fight the next 

day. General O’Connor sent one 9th Division battalion to join 

the cavalry units in establishing blocking positions. The battle 

seemed to end that night, but on 29 June, the South Vietnamese 

encountered and overran an entrenched enemy unit.

Operation Akron continued for a week and involved nine 

American, South Vietnamese, and Australian battalion-equivalent 

formations. It yielded only moderate results as the foe avoided 

combat. A break then ensued during which O’Connor received 

control of the Royal Thai Army’s “Queen’s Cobras” Volunteer 
73

Regiment, which he positioned in southwestern Bien Hoa Province 

to complete the encirclement of the Hat Dich. When Operation 

Akron II began at the end of September, the 1st Brigade and Rome 

plows reentered the Hat Dich looking for the enemy once more. 

Into the Mekong Delta

The Mekong Delta, which comprised all of IV Corps and 

the southernmost sections of III Corps, was the richest agricultural area in South Vietnam. Fed by the Mekong River that 

flows from Cambodia to the South China Sea, the Delta’s rich 

alluvial soil and teaming waterways generated over 75 percent 

of the nation’s food supply. The seventeen provinces southwest 

of Saigon also contained a wealth of manpower, its 6 million 

inhabitants representing about one-third of South Vietnam’s 

total population. During the first year of U.S. combat operations 

from mid-1965 to mid-1966, Westmoreland had relied on three 

South Vietnamese infantry divisions backed by around 3,000 

U.S. advisers and a dozen aviation companies to fight the war 

in the seventeen provinces southwest of Saigon. By the latter 

half of 1966, however, he and his South Vietnamese counterparts agreed that it would be necessary to station several U.S. 

brigades in the upper Mekong Delta to contain the Viet Cong 

main force battalions that were preventing the government from 

expanding its control into enemy-held areas of the countryside. 

With the U.S. 9th Infantry Division scheduled to arrive in South 

Vietnam at the end of 1966, General Westmoreland chose to use 

it to strengthen the allied position in the contested provinces 

south of Saigon.

The plan that Westmoreland brokered with the South 

Vietnamese government called for the 9th Division to station 

its 1st Brigade and division support area at Bearcat, just east of 

Saigon in Bien Hoa Province, its 3d Brigade in Long An Province, 

south of Saigon, and its 2d Brigade in Dinh Tuong Province 

immediately southwest of Long An Province. All three brigades 

would report to II Field Force even though the 2d Brigade would 

be operating in the IV Corps zone, thus allowing the senior 

adviser in IV Corps, Brig. Gen. William R. Desobry, to retain 

his focus on the advisory effort (Map 12). 

Another special feature of the 2d Brigade, 9th Infantry 

Division, was its amphibious role in the upper Mekong Delta. 

General Westmoreland paired the U.S. Army brigade with a U.S. 
Navy component known as Task Force 117 to create the Mobile 

Riverine Force, a versatile weapon that could reach enemycontrolled areas of the delta normally beyond the range of the 

road-bound South Vietnamese forces. The naval component was 

built around three squadrons. The first was a support squadron 

that performed headquarters, logistical, and housekeeping 

chores. The other two were assault squadrons designed to make 

amphibious landings. Each assault squadron contained about 

Map 12

ARVN

XXX

IV

2 9

X

OPERATION ENTERPRISE 13 Feb 67–10 Mar 68

OPERATION CORONADO I–XI 19 Jun 67–3 Mar 68

III CTZ

DONG TAM

MY THO

CAN GIUOC

GO CONG

CAN THO

Song Hau Giang (Mekong)

Song Co Chien (Mekong)

Song My Tho (Mekong)

Song Vam Co Tay

SOUTH CHINA SEA

GULF

O F

THAILAND

Song Vam Co Dong 

4

4

4

4

4

4

1

SAIGON

BAC LIEU

CHUONG THIEN

KIEN GIANG

AN GIANG

SA DEC 

KIEN

PHONG KIEN TUONG

DINH

TUONG

HAU NGHIA

LONG AN

KIEN

HOA

GO CONG

GIA DINH

BIEN

HOA

CHAU DOC

BA XUYEN

VINH BINH

VINH

LONG

PHONG

DINH

AN XUYEN

CAMBODIA

Corps Tactical Zone Boundary

Engagement

1966–1968

IV CORPS TACTICAL ZONE

0 50 Miles

0 50 Kilometers

74
75

one hundred landing craft that had been modified to create a 

variety of transport, command, medical, and fire-support vessels.

Additional fire support could be obtained by placing artillery on 

towed barges or helicopter-delivered platforms that would remain 

stable in waterlogged terrain. 

The first elements of the 9th Infantry Division arrived by 

ship at the port of Vung Tau, southeast of Saigon, in December 

1966. Under the leadership of Maj. Gen. George S. Eckhardt, the 

division spent the next few months completing its movement to 

theater. During that time, it conducted limited operations in the 

Rung Sat Swamp south of Saigon to hone amphibious warfare 

techniques, and supervised the construction of Dong Tam, an 

amphibious base that U.S. engineers were building just west 

of My Tho, the capital of Dinh Tuong Province, for the Mobile 

Riverine Force. 

In February, the division’s 3d Brigade, built around one 

mechanized and two light infantry battalions, deployed to Long 

An Province and began Operation Enterprise to secure Highway 

4, the vital route that linked Saigon with the Delta’s teaming agricultural bounty. With no North Vietnamese units in the area, the 

brigade operated with South Vietnamese Army and Regional and 

Popular Forces units to erode Viet Cong influence and to pacify 

the rural hamlets where insurgent sympathies remained strong. 

In April, the 3d Brigade dispersed one Viet Cong battalion and 

bloodied another, but the enemy returned with a vengeance. On 

2 May, a Communist battalion savaged a U.S. company during a 

night attack, killing seventeen Americans and wounding fortyeight. Following that assault, Viet Cong units avoided contact with 

the U.S. 9th Infantry Division in Long An Province for the next 

three months, preferring instead to target the South Vietnamese 

territorial forces that represented a direct threat to Viet Cong 

control over the rural population.

As the 3d Brigade continued Operation Enterprise in 

Long An, the 2d Brigade, 9th Infantry Division, moved into its 

newly completed base at Dong Tam and spent the early part of 

May operating in central Dinh Tuong Province to ensure that no 

Viet Cong units were preparing to strike the amphibious base. A 

major fight developed on 3 May when two U.S. infantry battalions 

discovered a Viet Cong local force company dug into the hamlet 

of Ap Bac (2), a traditional enemy stronghold where a Communist 

unit had famously repulsed a South Vietnamese attack supported 
76 

by U.S. helicopters in January 1963. This time, the results were 

different. Supported by armored personnel carriers, U.S. Air 

Force AC–47 Spooky gunships, and waves of armed helicopters, the infantrymen from the 9th Division encircled and 

then overran the Viet Cong unit, killing more than 200 enemy 

soldiers. The Communist troops did not die easily; it took fierce, 

close-range fighting to overcome their positions. Two men from 

Company A, 3d Battalion, 60th Infantry, later received the Medal 

of Honor for destroying no less than seven enemy bunkers, one 

soldier covering the other as they rushed forward to wipe out each 

position. American losses came to fifteen killed and twenty-seven 

wounded, most of them in the initial stage of the assault.

On 19 June, the 2d Brigade and Task Force 117 initiated the 

first phase of a long-running operation known as Coronado

designed to bring the Mobile Riverine Force into areas of the 

upper delta previously untouched by South Vietnamese units. 

The initial mission targeted a large enemy redoubt that stretched 

for eight kilometers from Can Giuoc, Long An Province, to Rach 

Cat. A South Vietnamese battalion protected the west flank 

along Route 230 as minesweepers led the way down the Rach Cat 

River followed by river assault boats, monitors, and command 

and control craft. Meeting no opposition, one infantry battalion 

landed with two companies north and east of the objective while 

the other landed two companies north and west of the target. 

After Col. Willam B. Fulton committed the brigade’s reaction 

force company by helicopter and the afloat reserve company came 

ashore to check on a suspected enemy location that proved empty, 

the brigade continued moving southward with the two battalions 

abreast.

The two companies advancing on the extreme left suffered 

heavy casualties when they walked into an ambush set by a 

local force Viet Cong battalion. Repeated company-sized attacks 

failed to penetrate the enemy’s position, but established a cordon 

on three sides by the time night fell. When they renewed their 

advance in the morning, the attacking battalions found the enemy 

had withdrawn. Although they found few bodies, prisoners and 

captured documents revealed the brigade had inflicted severe 

casualties on the Viet Cong.

The Mobile Riverine Force next moved into the Binh 

Xuan Secret Zone in northwest Go Cong Province. With South 

Vietnamese forces blocking to the southwest, U.S. troops landed 
77

on the morning of 4 July and established a series of patrol bases 

along two rivers that bordered the stronghold. Inserting infantry 

units by helicopter and landing craft to establish several ambush 

sites over a three-day period, the Americans suffered no casualties 

but killed or captured more than one hundred of the enemy. 

When intelligence detected a major enemy buildup in Dinh 

Tuong Province, Westmoreland ordered a thrust to eliminate the 

threat. In addition to the Mobile Riverine Force, he assigned the 

3d Brigade, 9th Infantry Division, and 1st Brigade, 25th Infantry 

Division, reinforced by South Vietnamese battalions, to assist. 

The plan called for the riverine force to sweep into the Cam Son 

base area from the south while a U.S. mechanized battalion and a 

South Vietnamese ranger battalion established blocking positions 

to the north. After clearing that area, the riverine force would 

enter the eastern part of the Ban Long redoubt while a brigade 

of South Vietnamese marines and the 25th Division’s 1st Brigade 

stood ready to reinforce. 

The two riverine battalions landed at five beaches in the 

southern Cam Son on 28 July and swept north. They met only 

fleeting resistance. Believing that the foe had withdrawn to new 

positions, South Vietnamese marines air assaulted into the 

Ban Long area of Dinh Tuong Province several days later and 

immediately took heavy fire. Although the marines could not 

take the position in five hours of heavy fighting, they launched 

another attack that night with U.S. artillery support. That attack 

failed as well, but the enemy found his escape routes blocked 

by a South Vietnamese ranger battalion and by two battalions 

of the 1st Brigade, 25th Infantry Division. Desperate, the Viet 

Cong tried to break the encirclement by attacking the marines 

the next morning. When that failed, some hid their weapons, 

split into small groups, and attempted to blend in with civilians. 

Others fled south toward the My Tho River or west and came up 

against the rangers.

After O’Connor reinforced the rangers with a U.S. mechanized infantry battalion, he sent the two riverine battalions to 

the confluence of the Tra Tan and My Tho Rivers with instructions to sweep east, and airlifted a battalion from the 3d Brigade 

to the opposite end of the battle area to sweep west. The three 

battalions thus formed a horseshoe-shaped cordon with the My 

Tho River and Ap Binh Thoi village in the center, as U.S. troops 

helped South Vietnamese police screen civilians for suspects. 
78 

Many of those questioned eventually admitted their membership in the local force battalion. The riverine forces redeployed 

elsewhere, but mopping-up operations continued until 4 August 

as the South Vietnamese 7th Division completed a series of 

sweeps that resulted in numerous, albeit minor, engagements 

that further punished the enemy.

The 2d Brigade continued Operation Coronado with a 

raid into Long An Province on 19 August when the riverine 

battalions landed at an overgrown pineapple plantation on the 

Vam Co Dong River and swept inland. The operation flushed 

part of a Viet Cong battalion out of its base and into adjacent 

rice paddies where helicopter gunships took a heavy toll of the 

fleeing unit. After three weeks of operations in conjunction 

with the 199th Brigade and South Vietnamese units in eastern 

Long An Province, and with other 9th Division elements in the 

marshy Rung Sat Special Zone east of Saigon, the 2d Brigade 

turned its attention to a familiar area in September.

Since the last time the 2d Brigade had conducted operations there, the Viet Cong had massed three or four main force 

battalions in Dinh Tuong Province. General O’Conner ordered 

Fulton, newly promoted to brigadier general as assistant division 

Operation Coronado National Archiv
79

commander exercising control over both the 2d and 3d Brigades, to 

Dong Tam. Col. Burt A. David, Fulton’s replacement in command 

of 2d Brigade, then led a push into the Com Son base area. After 

a South Vietnamese battalion on the north, a Regional Forces 

battalion on the east, and the mechanized battalion attached from 

3d Brigade on the northeast cordoned off the enemy redoubt, a 

riverine battalion swept north from landing sites on the My Tho 

on 12 September, but found no enemy. As the riverine soldiers 

continued their search the next morning, the mechanized battalion 

advanced into Ban Long from its blocking position on Route 20. 

A second riverine battalion went ashore, boarded helicopters, and 

landed immediately south and advanced in conjunction with the 

mounted unit. By 1200 the two battalions encountered resistance 

that became stiffer as they advanced, prompting Fulton to airlift 

another company from the unengaged riverine battalion to reinforce them. With the cordon not yet complete when night fell, the 

enemy broke contact and escaped.

The next day, 14 September, the South Vietnamese 7th 

Division reported that a large enemy force remained in a fortified area on the east bank of the Rach Ba Rai River, about ten 

kilometers upstream from its confluence with the My Tho. The 

A Navy assault craft of Task Force 117 during Operation Coronado. National Archiv
80 

2d Brigade planned to encircle the enemy with one battalion 

each from the north and south, and a mechanized battalion 

from the east, pinning the foe against the Ba Rai.

The operation began early on 15 September when the 3d 

Battalion, 60th Infantry, and its naval escorts followed minesweepers up the Rach Ba Rai. In the most dangerous phase of the 

operation, the convoy had to navigate a waterway that narrowed 

to only thirty meters wide, and which the enemy could easily 

control. As the convoy steamed upstream, the enemy opened 

fire from both banks with recoilless rifles, rocket-propelled 

grenades, machine guns, and small arms. The vessels’ armor 

plate prevented serious structural damage, and no boats were 

destroyed. The intense fire inflicted a number of casualties, 

however, especially among the sailors, and forced the vessels 

to retreat. After replacing the dead and wounded crewmen, the 

task force made a second attempt. Supported by artillery firing 

a rolling barrage that fell ahead and to both flanks, the vessels 

broke through and landed the troops.

With the northern beach finally secure, the 3d Battalion, 

47th Infantry, went ashore south of the enemy position. As a 

precaution, Fulton had ordered the mechanized 5th Battalion, 

60th Infantry, to change its planned westward attack northward. 

Taken as insurance if the enemy had opposed the landing of 

the 3d Battalion, 60th Infantry, the shift created a gap between 

it and the 3d Battalion, 47th Infantry. To close the gap, 2d 

Battalion, 60th Infantry, of the 3d Brigade air assaulted into the 

space between the advancing units as artillery and air strikes 

pounded the enemy. With its ranks already thinned from casualties sustained in the ambush on the river, the 3d Battalion, 

60th Infantry, advanced slowly. When darkness settled over 

the battlefield, the enemy broke contact and escaped through 

gaps in the cordon or swam across the Ba Rai. The next day, 

the Americans found a number of dead bodies amid the abandoned bunkers, but the five days of fighting had resulted in 

disappointment. 

Analy

In early October 1967 when Secretary of Defense Robert S. 

McNamara asked the Joint Chiefs for their strategy recommendations for the coming year. General Westmoreland approved the 

U.S.–South Vietnamese combined campaign plan that outlined 
81

their joint goals for 1968. The allies appeared to be making slow 

but steady progress in most areas of the war. During the first nine 

months of 1967 the allies had killed over 66,000 Communist 

soldiers while losing 17,000 of their own, 7,000 of whom were 

Americans. Naturally, both sides had deployed new soldiers to 

replace the fallen, yet even so Communist troop strength had 

declined by 20,000 men while allied strength had risen by 66,000. 

In addition to enjoying success in the war of attrition, the allies 

had made perceptible progress on the pacification front, increasing 

the percentage of the rural population living under government 

control from 44 percent to 48 percent as measured by MACV’s 

Hamlet Evaluation System. If North Vietnam could not reverse 

these trends, its prospects for victory were bleak.

Westmoreland believed that the allies had thwarted every 

major Communist offensive over the last year and were now in 

a position to start grinding down the enemy’s main force units 

and supply network faster than they could be replaced. MACV’s 

growing logistical strength, a spate of new airfield construction, 

and improvements in road security would soon allow the allies to 

conduct simultaneous division-sized operations in remote border 

areas of South Vietnam for months at a time, forcing the enemy 

to divert an ever greater part of his strength to defensive actions 

far from the populated lowlands. During the next six months, 

the MACV commander planned to push eight or more brigades 

into the enemy sanctuaries of northern III Corps and send the 1st 

Cavalry Division (Airmobile) rampaging through the interior of 

I Corps, hitting base areas formerly beyond reach of allied forces. 

As those operations diverted and then chewed up enemy main 

force units, South Vietnamese forces would gain extra breathing 

room to intensify the pacification program with assistance from 

the CORDS directorate of MACV. 

Another threat to Hanoi’s ambitions was the growing 

political stability of the South Vietnamese state. The transition of 

the Saigon government from a military junta to a democratically 

elected, constitutional republic came to fruition when Nguyen 

Van Thieu and Nguyen Cao Ky, after resigning their military 

commissions, won a national election as president and vice president, respectively. The 3 September 1967 election saw a national 

voter turnout of 83 percent. More rounds of voting scheduled for 

October and November would elect national legislators as well 

as province, district, and village officials. This time, the militant 
82 

Buddhists who had organized mass protests against the government in 1963 and in 1966 did not take to the streets. If the new 

South Vietnamese government succeeded in appealing to the 

political as well as economic aspirations of rural communities 

formerly alienated by Saigon, the Communists would lose some 

of their popular support and be forced to use harsher measures to 

enforce obedience. 

Allied progress, however, was not easy, quick, or irreversible. 

The enemy remained a powerful and pervasive force, nurtured 

by external sanctuaries, the infiltration of soldiers and equipment from North Vietnam, and a deeply rooted clandestine 

political apparatus that exercised varying degrees of influence 

over much of South Vietnam’s population. If the U.S. Army had 

hurt the enemy and thwarted many of his plans, it had not yet 

tilted the scale decisively in the allies’ favor. Most importantly, 

allied actions had not yet persuaded Communist leaders in 

North Vietnam to end their effort to conquer the South. Unless 

the allies could cripple the North or prevent it from sending in 

reinforcements and supplies, the war seemed likely to continue 

for many more years until one side or the other lost the physical 

or moral ability to continue to fight. This was what had happened 

during the Indochina War of 1945–1954, when the Communists 

had won control of northern Vietnam, not through conquest, 

but by bleeding the French until their will had broken. Believing 

the Communists would never be able to defeat the United States 

militarily, Chairman of the Joint Chiefs of Staff General Earl 

G. Wheeler predicted that the enemy’s only recourse was “to 

win this war in Washington, just as they won the war with the 

French in Paris.” Only time would tell if Wheeler was correct. 
83

The Author

Glenn F. Williams is the team leader of the commemorative 

office at the U.S. Army Center of Military History. A retired Army 

Infantry officer, he holds a Ph.D. in history from the University of 

Maryland. His publications include Year of the Hangman: George 

Washington’s Campaign Against the Iroquois (Westholme, 2006) 

and Dunmore’s War: The Last Conflict of America’s Colonial Era

(Westholme, 2017). He is a contributing author of The Panama 

Canal: An Army’s Enterprise (Center of Military History, 2009). 

Williams has also worked at the National Museum of the U.S. 

Army, the American Battlefield Protection Program of the 

National Park Service, and as curator of exhibits for the USS 

Constellation Museum. 

85

Further Reading

Albright, John, John A. Cash, and Allan W. Sandstrum. 

Seven Firefights in Vietnam. Washington, D.C.: U.S. Army 

Center of Military History, 1970.

Fulton, Maj. Gen. William B. Riverine Operations 1966–

1969. Washington, D.C.: U.S. Army Center of Military History, 

1985.

Garland, Albert N., ed. A Distant Challenge: the U.S. 

Infantryman in Vietnam 1967–1970. Nashville, Tenn.: The 

Battery Press, 1984.

———. Infantry in Vietnam. Nashville, Tenn.: The Battery 

Press, 1982.

MacGarrigle, George L., Combat Operations: Taking the 

Offensive, October 1966 to October 1967. The United States Army 

in Vietnam. Washington, D.C.: U.S. Army Center of Military 

History, 1998.

Marshall, S. L. A. Ambush and Bird: Two Vietnam Battle 

Narratives. Garden City, N.J.: Nelson Doubleday, Inc., 1969. 

———. Battles in the Monsoon: Campaigning in the Central 

Highlands, South Vietnam 1966. Nashville, Tenn.: The Battery 

Press, 1967.

———. Vietnam: Three Battles. New York: Da Capo Press, 

1982.

———. West to Cambodia and Fields of Bamboo: Two 

Action Histories of the Vietnam War. Garden City, N.J.: Nelson 

Doubleday, Inc., 1971.

Murphy, Edward F. Dak To: America’s Sky Soldiers in South 

Vietnam’s Central Highlands. New York: Simon & Shuster, 1993. 

Pearson, Lt. Gen. Willard. The War in the Northern 

Provinces 1966–1967. Washington, D.C.: U.S. Army Center of 

Military History, 1991.
86

Starry, Gen. Donn A. Mounted Combat in Vietnam. 

Washington, D.C.: U.S. Army Center of Military History, 1978; 

also published as Armored Combat in Vietnam. North Stratford, 

N.H.: Ayer Company Publishers, Inc., 1982.

Tolson, Lt. Gen. John J. Airmobility in Vietnam 1961–1967. 

Washington, D.C.: U.S. Army Center of Military History, 1989. 

For more information on the U.S. Army in the Vietnam War, 

please read our other titles in the U.S. Army Campaigns of the 

Vietnam War series published by the U.S. Army Center of Military 

History (www.history.army.mil).

nam War

The

Viet

50th Anniversary

PIN: 200909–000