Just east of Rockland , west of Route 45, their is a DNR parking area, Trail 3 goes right threw it. Parked for the day their several times shouldn't be a problem to stay overnight, also in Rockland Check with Peppermill Rentals .
Cindy and Darrel have rooms for trailers and would probably let you leave on their.
In Bergland I would call Tom @ the Bergland Bay bar and ask him.
We are located Rockland about 8-10 miles from Mass. You can park your vehicles down by our shop. There is plenty of space and we live right there. Just let me know. 906-886-2940.