I've been meaning to try the Beaver Brook Reservation since I hiked it last year. Meet at 10 am at Belmont Rock Meadow, on Mill St just South of Concord Ave in Belmont. I plan on skiing about 4 hours, we will go toward Waltham, but generally tour around. This area seems amazingly woodsy despite the suburban environment. Bring some snacks and water etc. I expect there will have been walkers about to pack the trails but we just might find some untracked stuff, recommend wear gators or pants that seal well with your boots to keep loose snow out and keep your feet dry!
Map link: https://plus.google.com/104026583632292991339/about?gl=us&hl=en