It was converted into a signal aircraft warning regiment after the United States entered World War II.

In 1924, the headquarters was relocated to San Diego, the Oregon and Washington units were inactivated, and the 1st and 2nd Squadrons moved to Los Angeles.

[3] Upon moving to Los Angeles, future United States President Ronald Reagan joined the regiment's Headquarters Troop as a second lieutenant on 18 June 1937.

The distinctive unit insignia consisted of a gold colored metal and enamel device 1 1/16 (2.70 cm) in diameter with a mission bell in the center of a yellow shield.

The coat of arms was of a similar design except that it omitted the motto and included the Organized Reserve Minuteman crest above the shield.