Bear Brook State Park, with over 10,000 acres, is the largest developed state park in New Hampshire. Located in the southeast region of the state, there is plenty to do and see for everyone. Forty miles of trails through the heavily forested park lead to seldom visited marshes, bogs, summits, and ponds. The park offers a day-use area, group areas, and a 101-site campground. Bear Brook State Park Campground Information. If archery is your sport, Bear Brook State Park boasts two archery ranges - one 15-target range maintained by the N.H. Fish and Game Department, plus an additional four-target practice range that is universally accessible. (Bring your own archery equipment.) A Museum Complex within the park which is home to New Hampshire Antique Snowmobile Museum, Old Allenstown Meeting House, and the Richard Diehl Civilian Conservation Corps (CCC) Museum. Most of the museums are housed in historic CCC buildings. Listed on the National Register of Historic Places, the Bear Brook Camp is one of the most complete camps remaining intact and in use in the country. The museums are open at various times throughout the summer.