During the 1968 Tet Offensive, the division conducted operations along the DMZ with a portion of the division fighting in the Battle of Huế. At the time, 3rd Marine Division intelligence estimated the combat strength of PAVN and Viet Cong (VC) forces in the DMZ area was 40,943 troops. The PAVN and VC stepped up their attacks by fire on every combat base in the division area of operations. This included daily attempts at interdiction of naval traffic on the Cua Viet River near Đông Hà. The division had to invest many of its assets to open the Cua Viet River to traffic. BLT 5/l, the Landing Force of SLF B, remained under the operational control (OPCON) of the division throughout February 1968. BLT 3/l continued Operation Saline under operational control of the 1st Amphibian Tractor Battalion with the mission of clearing the area adjacent to the Cua Viet River between Cua Viet and Đông Hà. BLT 2nd Battalion, 4th Marines, the Landing Force of SLF A, remained under operational control of the division throughout the month. BLT 2/4 conducted operations in the Lancaster II and Kentucky areas.