A formation of Oregon (OR) Air National Guard (ANG) F-15 Eagles are refueled in flight by a Washington (WA) ANG KC-135 Stratotanker during Exercise SENTRY EAGLE. The 173rd Fighter Wing (FW), Klamath Falls ANG, hosts SENTRY EAGLE, which is a bi-annual, two-day exercise that emphasizes learning tactics designed for defending friendly airspace and assets while participating with a multi-service military force