Ennnh - the closest airport to the flight origin that is:
- On US territory
- 747-capable
- physically remote, not just in km/miles, but also surrounded by swampland and its denizens (snakes and alligators). Avoids protests and general "eyes-on" observation and publicity.
A government op, yes - but Treasury, not so much CIA or "other."
I flew over TNT inbound to MIA, 30 or so years ago. Always wondered what that huge runway, with no other infrastucture to speak of, was doing out in the green water. but you can look it up.