Shield
Per fess Azure and Gules, in chief a Spanish castle and a prickly pear cactus Or, in base a key palewise Argent.
Crest
That for the regiments and separate battalions of the Idaho Army National Guard: On a wreath of the colors Or and Azure, an elks head caboshed Proper.
Motto
PREPARE THE WAY.
Shield
The blue is the color of Infantry, showing the original organization was Infantry. The red with the white charge gives the present Engineer colors. The castle represents the service during the Spanish-American War beyond the continental limits of the United States. The cactus symbolizes Mexican Border Duty, while the key is taken from the coat of arms of the City of Angers, France, where the Regiment was stationed during World War I.
Crest
The crest is that of the Idaho Army National Guard.
The coat of arms was originally approved for the 116th Engineer Regiment on 13 January 1930. It was redesignated for the 116th Engineer Battalion on 2 September 1943.