In August 1960, he was named chief of staff of the 1st Marine Brigade at Kaneohe.
He served in this capacity until May 1962, when he was deployed to Thailand as chief of staff of the 3rd Marine Expeditionary Unit.
He returned from Thailand in August 1962 and assumed duty as chief of staff of the 1st Marine Aircraft Wing, Aircraft, FMF, Pacific, Iwakuni, Japan.
The following June, he arrived in the United States, and assumed duty at Norfolk, Virginia, as assistant chief of staff, G-3, Fleet Marine Force, Atlantic.

In March 1964, he was promoted to brigadier general and assigned as legislative assistant to the Commandant of the Marine Corps, and was awarded the Navy Commendation Medal for service during this assignment.
Following his promotion to major general on January 19, 1967, he assumed duties the following month as commander, Marine Corps Air Bases, Western Area/Commanding General, Marine Corps Air Station El Toro, California and earned his third Legion of Merit.
In August 1960, he was named chief of staff of the 1st Marine Brigade at Kaneohe. He served in this capacity until May 1962, when he was deployed to Thailand as chief of staff of the 3rd Marine Expeditionary Unit. He returned from Thailand in August 1962 and assumed duty as chief of staff of the 1st Marine Aircraft Wing, Aircraft, FMF, Pacific, Iwakuni, Japan. The following June, he arrived in the United States, and assumed duty at Norfolk, Virginia, as assistant chief of staff, G-3, Fleet Marine Force, Atlantic.
In March 1964, he was promoted to brigadier general and assigned as legislative assistant to the Commandant of the Marine Corps, and was awarded the Navy Commendation Medal for service during this assignment. Following his promotion to major general on January 19, 1967, he assumed duties the following month as commander, Marine Corps Air Bases, Western Area/Commanding General, Marine Corps Air Station El Toro, California and earned his third Legion of Merit.
William G. Thrash