Way back in the mid 80's when I XCed, I remember a Laurel Mt SP trail map, that had part of the Laurel Mt ski area slopes marked on it.
Due to the simple cost of snowmaking, and the lack of natural snow, you are going to be hard pressed to find any "free" skiing in the area. On top of that, insurance issues often make it a nono to be skiing on a persons private property, without permission.
Where there is natural snow, some have posted that it is possible to earn some turns at the former Oregon Ridge Ski Area in the Baltimore area. It has also be rumored that those "in the know" can take some runs at the former White Mt ski area, which is hidden back behind Seven Springs. Don't some people go to TL or CV after the season ends to skin up and ski down?
Of course, if you go up to the NE, there is allways the Thunderbolt on Mt Greylock