Fort Sill is a United States Army post in Lawton, Oklahoma, about 85 miles southwest of Oklahoma City. Today, Fort Sill remains the only active Army installation of all the forts on the Southern Plains built during the Indian Wars. It is designated as a National Historic Landmark and serves as home of the United States Army Field Artillery School as well as the Marine Corps' site for Field Artillery MOS school, United States Army Air Defense Artillery School, the 31st Air Defense Artillery Brigade, the 75th Fires Brigade and the 214th Fires Brigade. Fort Sill is also one of the five locations for Army Basic Combat Training.