The north end of the headquarters was the ordnance storage room. This included a large room for the storage of cannon, harness and associated wheeled vehicles. There was also an ordnance storeroom where the ordnance sergeant maintained and repaired weapons. This is where various weapons were stored, such as sabres (50 per case), muskets (20 per case), and ammo (5,000 pistol flints per case and 1,000 musket buck & ball per crate). The sergeant had to maintain records accounting for all guns and ammo because any missing items were charged against a soldier's pay. The ordnance sergeant also was in charge of repairing malfunctioning weapons.

The fort has two 6 lb. field artillery guns or cannons that were used until 1853 for formal salutes and cermonies. The guns were pulled by six horses with the ammo being carried in a limber chest which served as a seat for three of the artillery crew members. It was reported that Indians thought they were being shot at by wagons when these guns were first put into use. They called the cannon thunder sticks or thunder wagons.