Azure a polar bear statant on an ice cake Argent: on a canton Or a fess Sable between three martlets of the like two and one.
That for the regiments and separate battalions of the Army Reserve: On a wreath of the colors Argent and Azure, the Lexington Minute Man Proper. The statue of the Minute Man, Captain John Parker (H.H. Kitson, sculptor), stands on the common in Lexington, Massachusetts.
III T bl K b Pb III A E T b (The Bayonet Decides).
The polar bear on its blue background is copied from the unofficial shoulder patch of the North Russian Expeditionary Force, of which this Regiment was a part during the years 1918-1919. The Regiment, organized in 1917, was made up to a large extent of men from Detroit, and was known locally as "Detroit's Own." The canton bears a part of the coat of arms of Cadillac, the founder of Detroit, and is symbolic of the origin of the Regiment and of its 1924 allocation. The motto is pronounced as though spelled in English "shtuk ryshayet." Literally translated it is the "The Bayonet Decides," freely translated it may be rendered "We Finish With The Bayonet."
The crest is that of the United States Army Reserve.
The coat of arms was originally approved for the 339th Infantry Regiment on 15 March 1924. It was redesignated for the 339th Regiment on 5 August 1960.