ShieldGules, between two flaunches Argent, each bearing a fleur-de-lis Azure, a Philippine sun Or charged at center with a saltire enhanced of the first above three bars wavy Vert.
CrestThat for the regiments and separate battalions of the Wisconsin Army National Guard: From a wreath Argent and Gules, a badger couchant Proper.
MottoSOLDIERS OF THE GREAT RIVER.
ShieldThe saltire, representing crossed sticks, symbolizes the strong support offered by the unit and also alludes to the fast game lacrosse adopted from the North American Indian, and namesake La Crosse, Wisconsin where the unit was organized. The gold and green wavy bars symbolize the Mississippi and the La Crosse Rivers and also reflect the green woodlands of the unit’s home area. The fleurs-de-lis refer to combat service in France during World War I. The colors green and red also allude to the French Croix de Guerre with Palm awarded the unit during World War I. The Philippine sun rays symbolize service in the Pacific in World War II and specifically the Philippine Presidential Unit Citation.
CrestThe crest is that of the Wisconsin Army National Guard.
The coat of arms was approved for the 173d Engineer Battalion on 22 July 1998. It was cancelled on 21 November 2014.