A gold color metal and enamel device 1 1/8 inches (2.86 cm) in width overall consisting of a green fir tree charged in chief with a gold five pointed star and in base a red fleur-de-lis, all in front of a blue wavy band, below a gold scroll bearing the inscription "POWDER RIVER" in black letters.
The green fir tree has been a traditional symbol used by the unit since 1919. The scarlet fleur-de-lis refers to courageous combat service in Europe during World War I and World War II. The gold star stands for the high achievements of the 91st Division training program, while the wavy blue band symbolizes the meandering Powder River that stimulated the famous battle cry of the 91st Division, "Powder River, Let'er Buck".
The distinctive unit insignia was originally approved for the 91st Division (Training) on 2 May 1968. The insignia was redesignated effective 17 October 1999, for the 91st Division (Training Support). It was redesignated effective 1 October 2009, for the 91st Training Brigade. The insignia was redesignated for the 91st Training Division effective 18 September 2010.