On a silver gray disc edged with a 1/8 inch (.32 cm) black border, 3 inches (7.62 cm) in diameter overall, a mountain of two peaks of alternating silver gray and black checks, below the arced inscription MONTBELLO in black letters 5/16 inch (.79 cm) in height.
The two mountain peaks allude to Colorado, the location of the school. They also represent the letter M.
The shoulder sleeve insignia was originally authorized 15 July 1980, and cancelled due to a new design and updated description and symbolism on 3 March 1981. It was amended to add subdued colors and metric measurements on 8 July 1992, currently amended to update the manufactured drawing on 28 February 2014. (TIOH Drawing Number A-10J-268)