Insignia Description
A gold colored metal and enamel device 1 1/8 inches (2.86 cm) in height overall consisting of a shield blazoned: Azure, an oak tree Or; in a chief dancette Gules fimbriated Argent three alerions of the second. Attached below the shield a red scroll turned gold inscribed "JAMAIS TROP TARD" in gold letters.

Symbolism
The shield is blue for Infantry and blue is also the color of the shield of the coat of arms of St. Mihiel. The dancette alludes to the three rocks on the coat of arms of St. Mihiel. The oak tree represents service in the Meuse-Argonne. The arms of Lorraine are "Or, on a bend Gules three alerions of the field," and the three alerions on the red chief denote service in Lorraine.

History
The distinctive unit insignia was originally approved for the 311th Infantry, Organized Reserves on 12 Apr 1922. It was redesignated for the 311th Regiment (BCT) on 8 Jul 1960.

Source: The US Army Institute of Heraldry