On a Black vertical oval embroidered item edged with a 1/8 inch (0.32 cm) Green border, 2 3/4 inches  (6.99 cm) in width by 3 1/2  inches (8.89 cm) in height, a stylized White buffalo head, in profile to the right, shaded Silver Gray, Black details on horns, nostril, pupil of eye, with White highlight on pupil and Green edging around eye, between the inscription MANTECA arcing above and HIGH SCHOOL below in White letters.

The school colors are Irish Green and White. The green symbolizes the hunter spirit of the cadet. The White buffalo is the school mascot, traditionally it is a sacred animal and symbolizes purity and truth. 

The shoulder sleeve insignia was originally authorized 11 December 1997, it is currently being amended to update the manufacturing drawings and to add the ACU color conversions on 28 November 2018. (TIOH Drawing Number A-10J-568)

On a shield shaped silver metal and epoxied device 1 1/4 inches (3.18 cm) in height blazoned as follows: Vert, a buffalo courant in train aspect Argent, garnished Argent (Silver Gray), hooves Celeste. Attached below the shield a Green scroll, with the inscription BRING ON THE COMPETITION in silver letters.   

Hunter green and white are the school colors. The buffalo is the schools mascot. "Bring on the Competition" is the school motto.

The shoulder loop insignia was originally authorized 11 December 1997, it is currently being amended to update the manufacturing drawings on 28 November 2018.