Air National Guard operating forces are structured where each of the 50 U.S. states, the Commonwealth of Puerto Rico, the territories of Guam and the U.S. Virgin Islands, and the District of Columbia of the United States, houses at least one wing. Each wing is either assigned aircraft, or aircraft are shared with a unit of the active duty Air Force or the Air Force Reserve under an "Associate" arrangement. The ANG of the territories of Guam and the Virgin Islands have no aircraft assigned and perform ground support functions. Air National Guard activities may be located on active duty air force bases, air reserve bases, naval air stations/joint reserve bases, or air national guard bases and stations which are either independent military facilities or collocated as tenants on civilian-controlled joint civil-military airports.
