The Royal Thai Air Base Nam Phong in Nam Phong District, Khon Kaen Province, Thailand was constructed in 1966-1967 during the Vietnam War by Utah Mining Company, originally to support EC-121 aircraft and potentially three tactical aircraft squadrons, but was ultimately completed as a "bare base" to support disbursal and theater force staging. The airfield was used by covert Laotian and Thai Special Operations Forces as part of Project 404 (aka-Palace Dog) and from 1969 through 1975. In June 1972 Nam Phong became a concurrent base of operations for United States Marine Corps air operations by Marine Aircraft Group 15, 1st Marine Aircraft Wing.