Middlesex Fells Reservation, 4 Woodland Road, Phone: +1 617-727-1199, . Over 2500 acres for hiking, horseback riding, rock climbing, or cross-country skiing. Includes 340 acre Spot Pond which offers sailing, kayak, canoe and rowboat rental during the summer. Sailing lessons are available. Off-road biking on fire roads. Large open picnic areas and more.
Friends of the Middlesex Fells, 4 Woodland Rd., Phone: +1 781-662-2340,. The volunteers that make it great.
New England Mountain Biking Association, . Maintains the bike trails here.