the chic chocs in quebec, the newfoundland fjords, mt katahdin, mt washington...there is backcountry skiing in the east, people just often over look it.
sugarloaf and jay would be my two choices for resorts. Both have some good sidecoutry too. I never hit it as i didnt have touring gear at the time, but there is a run on sugarloaf called kill switch off of the top of timberline dropping into the backside on the crocker side, instead of the burnt side. I guess its a huge chute through the trees that gets loaded up with snow, you need to either tour out or sled out. Bit random i know, but its just yet another thing on my east coast to do list if i make it back there in the winter at some point.