The Alaska National Guard does not fly fighters, only the USAF and the F-16's based out there. I don't know the altitude of the balloon over Alaska but I do know what it was over the continental US. As a civilian, I have flown with the Navy, Marines and the USAF twice, including an F-16 out of Shaw (79th FS, tail 91-468, a Block50) and a KCC-135 out of Seymour Johnson refueling F15E Strike Eagles. It was my business to keep up with this stuff jobwise. By the way, a Canadian based F-18 Hornet, actually fired on one of these balloons several years, thus, from experience, why we used an AIM-9X Sidewinder the other day. That was $400,000.00 worth of missile for that shot.