[4]: 181 The operation concluded on 19 January 1968 with the 1st Cavalry Division being ordered to move 350 km north from Landing Zone English in Bình Định Province to Camp Evans in Thừa Thiên Province as part of Operation Checkers, to increase the number of maneuver battalions in I Corps in order to support the besieged Marines at Khe Sanh Combat Base and defeat any other People's Army of Vietnam (PAVN) attack across the DMZ.

[5] The Bồng Sơn Plain was enclosed on three sides by mountains and bordered on a fourth by the South China Sea, this rich agrarian flatland supported a population of nearly 100,000, mostly farmers and fishermen.

[4]: 184–5 As the waves of helicopters flying north of LZ English signaled an abrupt end to the Tết truce, many enemy soldiers caught without weapons rushed from hamlets to seek safety in the jungle.

As groups of refugees began clogging the roads and slowing the US advance, local Viet Cong (VC) forces skillfully covered the withdrawal of their PAVN comrades.

The action began late on the afternoon of 18 February, when a rifle company from Smith's 1st Brigade found the 22nd Regiment's 9th Battalion in a fortified hamlet, Tuy An, at the base of the mountains west of Tam Quan.

During December Norton's men had severely mauled the unit, its discipline and morale broken to the extent that the 3rd Division considered the 18th the least reliable of its three regiments, but after receiving replacements and undergoing extensive retraining, the 18th was again prepared to fight.

On 6 March an air cavalry pilot on a routine dawn patrol north of the Tra O Marsh, 16 km southeast of LZ English, spotted a man disappearing into a foxhole outside Hoa Tan hamlet.

The commander of the 1st Squadron, 9th Cavalry, Lt. Col. A. I. T. Pumphrey, quickly ordered one of his aero-rifle "blue team" platoons stationed at Landing Zone Two Bits to rescue the abandoned door gunner and then investigate the situation around Hoa Tan.

This frustrating situation changed shortly after midnight on 18 March, when a South Vietnamese Popular Forces outpost at Sa Huỳnh Base, a small port north of the Bình Định-Quảng Ngãi border, reported human-wave attacks by an estimated two battalions that threatened to overrun its position.

The following evening, 19 March, while looking for a place to settle in after a hot, unproductive day in the jungle, one of Smith's rifle companies stumbled upon a PAVN unit in Trường Sơn hamlet, 18 km north of LZ English.

At the same time a helicopter hovered overhead, illuminating the PAVN's positions with flares, while gunships raced in to add rockets and machine guns to the incoming artillery fire.

Nevertheless, by early April it was evident that the 22nd had slipped north into the mountains of southern Quảng Ngãi with only its 8th Battalion remaining in Bình Định, shunning combat and well hidden in the An Lão Valley.

As the Americans probed southward they encountered small groups of PAVN soldiers attempting to escape, but not until 8 April did they come upon the main body of the 22nd Regiment's 8th Battalion in the recently abandoned hamlet of Hung Long.

Received on 30 March from the 4th Infantry Division, they required careful route reconnaissance and shallow stream fords, but succeeded in holding down US losses at Hung Long.

Then, while units of Norton's 3rd Brigade screened the high ground on either side of the valley, two Vietnamese Marine battalions, chosen because they had no home ties in the region, moved north up the defile.

By April 1967, however, despite the cannibalization of many of its support elements to fill the infantry units and the arrival of large numbers of replacements from North Vietnam, the division would remain ineffective for most of the year.

In the 1st Cavalry Division operational area, Norton estimated that 80 percent of the people had been removed from insurgent influence, at least temporarily, although they were not necessarily under the control of the South Vietnamese government.

There, the brigade found caretaker units, ammunition and weapons caches and several sophisticated base camps, but failed to locate its major objective, the headquarters of the 3rd Division.

By this time the 3rd Brigade was back on the coast, and on 7 August, the new division commander General John J. Tolson sent Colonel McKenna's troops into the Song Re Valley in Quảng Ngãi Province, 20 km west of Ba To.

On the morning of 9 August, one cavalry company conducted an air assault onto three small hills, an objective called Landing Zone Pat (14°53′17″N 108°31′05″E / 14.888°N 108.518°E / 14.888; 108.518), 15 km north of Gia Vuc.

Mentioned frequently in the reports was LZ English, the division's large logistical base on the southern Bồng Sơn Plain just north of the Lai Giang.

In October American intelligence detected a reconstituted headquarters of the 22nd operating from the Cat Mit Mountains in Quảng Ngãi Province, far removed from its three battalions presumably still hiding in the Bình Định interior.

Again Tolson nominated the 3rd Brigade, and the unit left Bình Định, this time for good, on 1 October, leaving only four cavalry battalions in the coastal province once deemed critical.

Tolson partially converted the mechanized battalion into an airmobile force, concentrating its armored personnel carriers at the 2nd Brigade's base camp, Landing Zone Uplift.

The cost had been high, however with 498 troopers killed and 2,361 wounded, but the successes also showed that the PAVN was still trying to contest Bình Định Province, albeit with only poorly trained troops and recent replacements.

When a helicopter crew sent to investigate the intelligence report spotted an antenna protruding from a bunker near Dai Dong, he landed an aerorifle reconnaissance squad, known as a Blue Team, to check it out.

According to the official history of the PAVN 3rd Division, between September 1967 and January 1968, their units on the northeastern coast of II Corps "suffered [so] many reverses and casualties... that heavy infiltration of North Vietnamese Army troops was still not enough to fill the gaps."

Success in the lowlands convinced Westmoreland that he could safely transfer the 1st Brigade of the 1st Cavalry Division from Bình Định Province to northern I Corps nearly a month ahead of schedule.

Westmoreland was taking a gamble by leaving the province so thinly defended, but he judged that northern I Corps rather than the central coast would be the theater of decision in the coming weeks.

[6]: 203–4 In conjunction with Pershing from 26 May 1967 to 27 January 1968 the 1st Cavalry Division, ARVN and the South Vietnamese 816th National Police Field Force Battalion conducted Operation Dragnet to root out the VC infrastructure in Bình Định.