I know I'm probably just adding fuel to the fire of this flame but I can't help myself. Yes, pretty much all tree skiing on the east coast is manmade. The funny thing is the only real exception is Jay Peak, where you can cruise all around area's like the dip or way beyond beaver pond where the spacing just happens to be perfect by nature. Certainly a lot of Jay has been man-made as well...
Me and a few friends cut a new glade on Mittersill last summer. Quite honestly, I didn't find it to be the backbreaking labor whatshisname discribed it as; and franconia notch is way more densely forested than jay, vt. Three days and it was done, but the third day there were six of us and we had all the right tools. This is not a trail you're likely to stumble upon, and without a good idea of the geography you could get yourself into trouble real fast. There's at least a hundred feet of natural woods from the last (manmade, somewhat hidden, out of bounds) glade that you have to bushwack your way through. But the Cannon locals love that kind of stuff, and they have already begun to discover it.
And you know what, I don't mind too much if someone follows my tracks and finds the trail. The issue really isn't the work I put into it, it's just that someone could potentially steal my powder stash. It does feel like stealing, but this is public land and no one owns the snow. The real crime was cutting the trail in the first place. If you're worried about someone riding your powder get away from Jay. It's not a huge mountain and it's getting more and more touristy. The in bounds glades are tracked out so fast it's only natural that everyone starts riding out of bounds...