[1]: 346  On 17 December the battalion moved by road from Dong Ha Combat Base into the Co Bi-Thanh Tan corridor where they initiated Operation Chinook.

[2]: 78  They were relieved by the 1st Battalion 9th Marines on 22 November and then conducted small-unit patrols and company-size sweeps with Army of the Republic of Vietnam (ARVN) forces in the CoBi-Thanh Tan area.

[2]: 79  On 13 December the battalion redeployed by air to Khe Sanh, they conducted a four-day sweep of a ridge line west of the combat base, then settled into new positions.

[4]: 301–3  BLT 3/26 then joined Operation Taylor Common on 10 February until they were relieved on 20 March and went to An Hoa Combat Base for rehabilitation.

[5]: 27–8  Battalion companies protected the Nam O Bridge, where Route 1 crosses the Cu De River and held positions on Hills 190 and 124 and Outpost Reno.

[5]: 32  As part of Operation Keystone Bluejay the regiment stood down for deactivation in late February to early March with the 1st Marines taking over most of their tactical area of responsibility.