[2] On 21 January, COMUSMACV General William Westmoreland ordered General John J. Tolson to move the 1st Brigade, 1st Cavalry Division from Landing Zone El Paso to Quảng Trị City in order to relieve the 3rd Marine Regiment and to move the 3rd Brigade from the Quế Sơn Valley to Camp Evans, to relieve the 1st Marine Regiment.

While the 2nd Battalion, 502nd Infantry Regiment remained to defend LZ El Paso, Cushman sent his 1st Battalion, 502nd Infantry Regiment, to LZ Betty on 27 January to defend the facility, while the 1st Brigade, 1st Cavalry conducted operation against Base Area 101.

On 30 January Cushman sent his 1st Battalion, 501st Infantry Regiment, to LZ Jane 10km southeast of Quảng Trị near Highway 1 and Hải Lăng town, to assist the 1st Brigade, 1st Cavalry operations against Base Area 101.

[3]: 273 On 25 January the 3rd Brigade, 1st Cavalry Division commanded by Col. James O. McKenna began arriving at LZ El Paso and was then moved by helicopter and truck to Camp Evans.

[3]: 273 On the night of 30/31 January the PAVN and Vietcong (VC) launched their Tet Offensive attacking targets across South Vietnam.

In Quảng Trị the PAVN 812th Regiment (reinforced), of the 324th Division and the VC 814th Main Force Battalion attacked the city at 02:00 on 31 January and launched mortar and sapper attacks on LZ Betty, LZ Sharon and the Army of the Republic of Vietnam (ARVN) La Vang Base.

Company B then walked into an ambush north of Que Chu and was pinned down in the open with little cover, they were only able to withdraw after calling in close artillery support.

[6]: 347–9  On 9 February 5/7th Cavalry resumed their advance with artillery support from PK-17 and naval gunfire, they overran Lieu Coc finding PAVN bodies and fighting positions.

5/7th Cavalry would be stalled north of La Chu for two weeks, probing but failing to penetrate the PAVN defenses.