Janet Air ???
 

I realize that Janet are usually white with red window stripe but...?? In this image you can almost make out a low-vis N number above and behind rear door.

http://cryptome.org/2012-info/dulles-mystery/pict21.jpg


Source and more photos Cryptome.org ; Unmarked Aircraft at Dulles Airport

aren't those the Vision 767's?

That's vision.

I don't think Janet flies to places that have grass and trees.

Janet 737's are strictly from henderson to groom/tonopa. If they ( certain people ) needed to be at another location they would most likely fly on the beechliners they have or through commercial.

Thanks guys, Did some quick research. Google image search term "vision+airlines" bring one of those blue stripe 767s on page one. Paint job was a bit hard to find.
Also from what I can figure 'Janet' is pretty transparent. It appears to display their 'N' number under and behind the trailing edge of wing on all the aircraft I can find... And yes far too much greenery and trees..:)

Thanks again