[1]: 346 On 4 May 1967 the battalion was flown from Phu Bai to Khe Sanh Combat Base to support the Marines engaged in The Hill Fights.

[3]: 61 [2]: 47  The 26th Marines conducted Operation Ardmore a search and destroy mission in the Khe Sanh area from 17 July to 31 October.

[3]: 344  On 22 July the battalion was moved north to Phu Bai to replace the 5th Marine Regiment conducting Operation Houston.

[3]: 346–7  On the conclusion of Operation Houston on 12 September the 26th Marines were moved south to the Da Nang tactical area of responsibility (TAOR).

[3]: 414 At the beginning of 1969 the battalion was responsible for security on the northern approaches to Da Nang including the Hải Vân Pass.

[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.