There's a similar base in the UK at Menwith Hill. They don't welcome visitors as such, but activist/comedian Mark Thomas discovered that due to a quirk in a law, it was legal to fly a hot air balloon over it.
So that's what he did:
http://www.youtube.com/watch?v=IBksQsAZ2hQ (short version)
http://www.youtube.com/watch?v=epWTJUajIdI (full episode)