Sentry Eagle is a joint Air National Guard (ANG), Air Force, and Navy air-to-air combat training exercise hosted by the 173^rd Fighter Wing at Kingsley Field in Klamath Falls, Oregon. Sentry Eagle debuted in 1986 as a means of improving combat effectiveness, originally a yearly event until 1990 when it was changed to a biennial event.  The small airfield of Kingsley Field becomes very busy as 40 to 50 aircraft from about a dozen squadrons arrive for the four day exercise and open house.