A gold color metal and enamel device 1 1/8 inches (2.86 cm) in height consisting of a blue ring divided by gold lines into eleven equal segments separated at right center by a white disc, the ring enclosing a stylized plumb bob divided vertically with white at left and scarlet at right and having a gold triangle-shaped aperture at top center.
Scarlet and white are the colors used for the Corps of Engineers. The plumb bob and the masoned ring (suggesting a fortification), are symbolic of Engineer functions. The blue of the ring (signifying water), and the white disc simulating a pearl, together allude to the Pearl River which flows by Monticello, Mississippi, the units home station. The Battalions numerical designation in Roman numerals) is suggested by the blue C for 100, the V-shape and vertical centerline for six.
The distinctive unit insignia was approved on 28 July 1971. It was rescinded on 16 August 1976.Note: A coat of arms was not approved for this Battalion.