The last major offensive by the 3rd Marine Division in Vietnam, resulting in a tactical success but failing to halt North Vietnamese infiltration.
Key Facts
- Duration
- 22 January – 18 March 1969
- Days of combat
- 56 days
- Main US unit
- 9th Marine Regiment, 3rd Marine Division
- Area of operations
- A Shau and Song Đa Krông Valleys
- Award received
- Army Presidential Unit Citation
- Opposing PAVN unit
- 9th Regiment (PAVN)
By the Numbers
Location
Cause → Event → Consequence
Intelligence reports and captured documents indicated that the People's Army of Vietnam's 9th Regiment was operating in the A Shau and Song Đa Krông Valleys, using them as infiltration corridors to funnel men and matériel into South Vietnam, prompting U.S. command to authorize a major sweep operation.
From 22 January through 18 March 1969, the 9th Marine Regiment and attached units conducted Operation Dewey Canyon, a 56-day combat sweep through the PAVN-dominated A Shau and Song Đa Krông Valleys in Vietnam, engaging the PAVN 9th Regiment in what became the 3rd Marine Division's last major offensive of the war.
The operation achieved tactical success and earned the 9th Marine Regiment and attached units the Army Presidential Unit Citation, but it did not permanently interdict the flow of North Vietnamese troops and supplies into South Vietnam, limiting its strategic impact.
Belligerents & Mobilization Analysis
Side A
1 belligerent
Side B
1 belligerent