Chronology of Significant Events

1 January	III MAF strength totaled 65,789.
6 January	Operation Deckhouse V, the first major offensive by U.S. forces into the Mekong Delta, began with helicopter and waterborne landings by the SLF and Vietnamese Marines. The Viet Cong knew of the operation in advance and departed before the Marines landed.
26 January	MACV headquarters completed its Practice Nine Requirement Plan for constructing a strong point obstacle system (SPOS) south of the DMZ.
26 January	Operation Desoto began. Task Force X-Ray controlled this operation which involved elements of the 4th and 5th Marines in a search and destroy mission in Quang Nam Province. The operation lasted 73 days.
31 January	Operation Prairie, the 3d Marine Division's multi-battalion operation, which began in August 1966, ended in Quang Tn Province. The operation opposed elements of two North Vietnamese divisions.
1 February	The 3d Marine Division began Operation Prairie II, a continuation of Prairie I.
8-12 February	These dates marked the ceasefire for Tet, a major Vietnamese holiday. Thereafter, North Vietnamese units, for the first time, defended key terrain from well-constructed, fortified lines and employed artillery weapons ranging from 82mm to 130mm in size
12-22 February	The 1st Marines conducted Operation Stone in Quang Nam Province. In this operation, Marines destroyed a vast network of caves, tunnels, and bunkers. In the operation's second phase, Marines surrounded elements of the R-20 Battalion and then swept back and forth over the cordoned area.
21 February	Dr. Bernard Fall, noted historian of the French combat experience in Indochina, died in a explosion of an enemy mine. Dr. Fall was accompanying the 1st Battalion, 9th Marines on Operation Chinook II.
26 February	The 1st Marines began Operation Lafayette, a multi-battalion effort in Quang Nam Province.
10 March	III MAF completed the introduction of the M-16 to Marines in Vietnam.
18 March	The first woman Marine to serve in Vietnam, MSgt Barbara J. Dulinsky, arrived in Saigon, for assignment to the MACV combat operations center.
18 March	The 3d Marine Division ended Prairie II and began Paririe III the following day. The latter continued until 20 April.
26 March	COMUSMACV ordered III MAF to prepare a plan for locating, constructing, and occupying a strongpoint obstacle system south of the DMZ.
5 April	The 4th Marines began a multi-battalion operation named Big Horn in Thua Thien Province.
6-10 April	The 1st Marines conducted Operation Canyon with South Vietnamese ranger battalions participating.
20 April	Operation Prairie IV began in Quang Tn Province. It ended on 17 May.
20 April	Task Force Oregon arrived at Chu Lai.
24 April	The First Battle of Khe Sanh began. Units of the 3d Marine Division subsequently fought bitter battles with regular NVA forces for control of Hills 881S, 881N, and 861. This battle continued into May.
2 May	11th Engineer Battalion completed clearing a 200-meter wide trace between Con Thien and Gio Linh and began clearing a 500-meter perimeter around each position.
13 May	The 26th Marines began Operation Crockett in the Khe Sanh area.
18 May	Units of the 3d Marine Division, augmented by the SLF and ARVN forces, began Operation Hickory by moving into the southern portion of the DMZ in a three-pronged attack against North Vietnamese units using the area as a sanctuary.
26 May	The 5th Marines began Operation Union II, which continued until 5 June.
31 May	Lt. Gen Robert E. Cushman, Jr., succeeded LtGen Lewis W. Walt as CG, III MAF.
7 June	A company-size force from the 26th Marines engaged an NVA force on Hill 881 during Operation Crockett and reported killing 59 NVA soldiers.
14-22 June	The 7th Marines conducted Operation Arizona with a multi-battalion force. The operation moved 1,650 refugees to camps at Duc Duc, the headquarters of the An Hoa industrial complex 15 miles south of Da Nang
18 June	III MAF published its OpPlan 11-67 outlining the SPOS concept.
25 June	LtGen Cushman and MajGen Hoang Xuan Lam, the Vietnamese Army I Corps commander, opened the new 1,680 foot prefabricated bridge across the Da Nang River.
3 July	North Vietnamese artillery fired supply dumps at the Marines' base at Dong Ha.
14 July	The name "Dye Marker" became effective as the title of the efforts to construct an SPOS south of the DMZ.
15 July	An early morning enemy rocket attack heavily damaged aircraft and the southern end of the Da Nang Air Base.
28-29 July	The 3d Marine Division sent the 2d Battalion, 9th Marines, reinforced with armored vehicles, into the DMZ north of Con Thien on a search and destroy mission. The battalion had to fight its way out on the DMZ on the second day.
7-11 August	BLT 1/3 of the SLF conducted Operation Beacon Gate southeast of Hoi An.
10-28 August	The 1st Marine Division's Task Force X-Ray conducted Operation Cochise in Quang Tin Province in conjunction with the ARVN Operation Lien Ket-122.
27 August	The 1st Battalion, 7th Marines began Operation Yazoo in Happy Valley near Da Nang. There was little contact and the operation ended on 5 September.
3 September	North Vietnamese artillery fire destroyed the large ammunition dump at Dong Ha.
4 September	Navy Chaplain Vincent R. Capodanno died earning the Medal of Honor while serving with the 3d Battalion, 5th Marines.
4-15 September	Task Force X-Ray's Operation Swift pitted elements of two Marine battalions against a large and well-equipped force of NVA soldiers northwest of Tam Ky. ARVN forces and elements of Task Force Oregon fought simultaneous operations in conjunction with Swift.
6 October	BGen Harry C. Olson relieved BGen James E. Herbold, Jr., as commander of the Force Logistics Command
11-20 October	The 1st Marines conducted Operation Medina near Quang Tn.
20 October	The 1st Marines began Operation Osceola
24 October	The 7th Marines began Operation Knox, which ended 4 November, in the Phu Loc-Hai Van area.
31 October	Operation Ardmore, Fremont, and Kingfisher, which began in mid- July, ended in northern I Corps.
1 November	Vice President Hubert H. Humphrey, on a visit to South Vietnam, presented the Presidential Unit Citation to the 3d Marine Division and the 7th ARVN Airborne.
14 November	MajGen Bruno A. Hochmuth died in a helicopter crash near Hue. BGen Metzger assumed command of the 3d Marine Division pending the arrival of MajGen Tompkins.
6-17 November	The 5th Marines conducted Operation Essex in Quang Nam Province.
13-30 November	The 7th Marines conducted Operation Foster northwest of An Hoa.
1-31 December	The 3d Marine Division continued Operation Scotland, Lancaster, Kentucky, Napoleon, Neosho, and Osceola.
23 December	The 7th Marines terminated Operation Citrus
31 December	As of this date, III MAF units had expended 757,520 man days and 114,519 equipment hours on the construction of the strong point obstacle system, which many Marines referred to as the "McNamara Line." Enemy action had destroyed $1,622,348 worth of Marine equipment being used on the project.