A gold color metal and enamel device 1 1/8 inches (2.86 cm) in height overall consisting of a blue semi-circular background bearing a sea lion with a sword in the right paw and an arrow in the left, with a fleur-de-lis within the loop of the tail all gold and all between two white castle towers, each bearing a gold star all above a three spiral horizontal scarlet scroll lined gold and inscribed DUTY HONOR INTEGRITY all in gold letters.
Scarlet and white are the colors used for the Corps of Engineers and castle towers are symbolic of the Corps. The towers and sea lion allude to the Arms of Manila and refer to the units campaign there in the War with Spain, as well as the campaign in Manila during the Philippine Insurrection, with the stars indicating the Laguna de Bay and San Isidro campaigns. The spiral scroll simulates water and the blue area an island and together they refer to the units participation in the Guadalcanal and Northern Solomons campaigns, the dark blue, gold and scarlet referring to the Presidential Unit Citation (Navy) award for the latter, and red, white and blue denote the Philippine Presidential Unit Citation for the Leyte and Southern Philippines campaigns, World War II. The arrow and colors comprising the design were taken from the crest of the North Dakota Army National Guard and indicate the organizations home.
The distinctive unit insignia was approved on 8 July 1971.