Argent, on a pale emitting in saltire four lightning flashes Azure (Teal Blue) a key ward to dexter in base, the bow a bear's head, Or.
SENTINELS OF SECURITY.
Teal blue and white were the colors used for the U.S. Army Security Agency, the original designation of the organization. The key symbolizes the unit's mission-the guarding of security-and the golden bear's head on the key represents the State of California, where the unit was activated. The lightning flashes, symbolic of electricity, relate to the importance of electronic communications as part of the unit's functions.
The coat of arms was originally approved for the 309th Army Security Agency Battalion, Army Reserve, on 12 February 1959. It was assigned for use by the 325th U.S. Army Security Agency Battalion, Army Reserve on 5 August 1959. It was reassigned for use by the 309th U.S. Army Security Agency Battalion on 2 August 1965. It was cancelled on 6 June 1975. The coat of arms was reinstated and redesignated for the 309th Military Intelligence Battalion on 10 October 1995.