Shield
Azure, a fess Gules fimbriated Argent in chief the head of a bald eagle erased.
Crest
On a wreath of the colors, Argent and Gules, a lion rampant triple queued Or, armed and langued of the second, gorged with a collar Azure edged of the third and holding in its dexter paw a key of the like; at his feet a branch of laurel Or fructed Gules.
Motto
NOSTRUM EST (The Task Is Ours - Nostrum Est Opus).
Shield
The eagle's head, which is that of "Old Abe," the mascot of the Iron Brigade, First Corps, Army of the Potomac, links the history of the Iron Brigade with the 101st Division. It has been chosen as the predominating figure in the shoulder sleeve insignia of the 101st Division. The fess is scarlet piped with white, the colors of the Corps of Engineers, and the blue field and gold eagle's head show the colors of the flag of the State of Wisconsin.
Crest
The gold lion, a prominent symbol in the arms of the Normandy Province of France, Belgium and the Netherlands, is shown with three tails, signifying those three areas where the Battalion's service in World War II earned them the French and Belgian Croix de Guerres and the Netherlands Orange Lanyard. The blue collar on the lion denotes the Presidential Unit Citation which they also received for service in Normandy and Bastogne. The key and branch of laurel refer to the two decorations awarded the unit while serving in the Republic of South Vietnam, namely the Cross of Gallantry with Palm and the Civil Action Medal.
The coat of arms was originally approved for the 326th Engineer Regiment on 21 May 1925. It was amended to correct the wording of the blazon on 15 October 1926. The insignia was redesignated for the 49th Airborne Engineer Battalion and amended to delete the Organized Reserves crest on 7 March 1951. On 1 August 1956, it was redesignated for the 326th Airborne Engineer Battalion. The insignia was redesignated for the 326th Engineer Battalion on 26 March 1958. The coat of arms was amended to add a crest on 29 March 1973.