However, having flown B777 test flights out of Everett on a weekend (i.e. 'G') and out of places like Glasgow Montana (not the 'international airport, the ex USAF base owned by Boeing) where there is Nothing in the way of airspace, ATC always provide a service.
Actus,
That was because you were in Class E ( tower airspace reverts to E when an FAA Class C or D tower is closed) and elsewhere there is very little G in US, it's E down to 1200/700 agl.
Tootle pip!!