Possible military test craft in Oak Harbor, Washington.

I was driving and saw and oddly shaped aircraft.  It left no trail.  I could not tell whether it made any noise because I was driving a very noisy car at the time.  If you looked at the craft from the bottom, it appeared to be shaped a bit like a chevron.  As it flew away and I saw it from behind, its appeared to be curved.  It was one solid body, somewhat like the Stealth, except the wings (if you can call them that) were curved downward.  I doubt it was an alien craft because it was flying very low and there was a military base close by.  But it was certainly unlike anything I'd seen before or since.
Date of the event may be approximate.  PD