Question: How many murder victims were found on a 1000 acre+ preserve located in Allenstown, New Hampshire?

Context paragraphs:
Mark's and Jack's Island Natural Area Preserve: Mark's and Jack's Island Natural Area Preserve is a 2000 acre Natural Area Preserve located in Accomack County, Virginia.  The preserve supports Chesapeake Bay beach habitat, as well as various types of marsh, shrub, and forest vegetation.  Many species of birds can be found in the preserve's wetlands, and numerous plant species live in the marsh, including marsh-elder.  Loblolly pine and black cherry may be seen along the tops of some old dunes.  The beaches provide a home for the northeastern beach tiger beetle.

Redrock Mountain Natural Area Preserve: Redrock Mountain Natural Area Preserve is a 640 acre Natural Area Preserve located in Smyth County, Virginia.  The preserve is named for the 4413 ft Redrock Mountain, which itself is named for its red siltstone cliffs.  It supports a number of rare natural features, and two natural community types, including examples of "mountain/piedmont basic woodlands" upon the mountain's slopes, and "rich cove/slope forests" in the preserve's lowlands.  Five rare plant species are found on the property, including spring blue-eyed Mary ("Collinsia verna"), fringed scorpion-weed ("Phacelia fimbriata"), and Carey saxifrage ("Saxifraga careyana").

Allenstown Meeting House: The Allenstown Meeting House (also known as Old Allenstown Meeting House; Church of Christ; Christian Church) is a historic meeting house on Deerfield Road in Allenstown, New Hampshire.  It is a single-story wood-frame structure with a gable roof, resting on a granite foundation.  It has a heavy timber frame and is sheathed in wooden clapboards.  The main facade faces the road to the south, and is five bays wide, with a central door flanked by two windows on either side.  The interior has retained its original box pews and pulpit.  The northwest corner of the building was damaged by arson fire in 1985, but has been sensitively restored.  The meeting house was built in 1815, and served as the town's main civic and religious building from then until 1886, when it was abandoned for both purposes.  It is the only surviving single-story meeting house of the period in New Hampshire.

List of unidentified murder victims in California: In California, there are many murder victims in the category of unidentified decedents, whose identities remain unknown.  In most of these cases, their murderer has never been identified.

Difficult Creek Natural Area Preserve: Difficult Creek Natural Area Preserve is an 819 acre Natural Area Preserve located in Halifax County, Virginia.  The preserve aims to restore a portion of Virginia's southern Piedmont to pre-settlement conditions, when the region was dominated by savannas maintained through a natural fire regime.  These savannas featured open, prairie-like areas with scattered pines and hardwoods.  Management of the preserve includes utilizing prescribed burns and removing loblolly pine plantations to restore the former landscape.  Several rare plants, remnants of the original prairie vegetation, survived by colonizing roadsides and power lines; these plants are now protected and encouraged within the preserve.

Grassy Hill Natural Area Preserve: Grassy Hill Natural Area Preserve is a 1440 acre Natural Area Preserve located in Franklin County, Virginia, just to the west of the town of Rocky Mount.  The site is composed of rocky slopes with various hardwood species and patches of Virginia pine.  Shallow basic soils, typified by heavy clay, are found among bedrock outcrops rich in magnesium.  Rare woodland communities live upon these substrates, and numerous rare plants may be found within grassy forest clearings near the summit.  Evidence at the preserve suggests that the majority of the site was once more open, and may have historically been maintained through a natural fire regime that has been suppressed during modern times.

Mutton Hunk Fen Natural Area Preserve: Mutton Hunk Fen Natural Area Preserve is a 516 acre Natural Area Preserve located in Accomack County, Virginia.  Fronting on the Atlantic Ocean's Gargathy Bay to the east, it is also bounded by Whites Creek and Mutton Hunk Branch to its north.  The property contains a rare "sea level fen" community, one of only four in Virginia.  Despite the proximity to the ocean's saltwater, freshwater wetland plants are able to survive in this environment due to the influence of freshwater springs.  Acidic conditions also encourage the growth of plants normally found in bogs, in addition to tidal freshwater wetland plants; five of the species found at the preserve are regionally rare.

Bear Brook State Park: Bear Brook State Park is a 10000 acre + preserve located in Allenstown, New Hampshire, and surrounding towns.  It is one of New Hampshire's largest state parks.

List of protected areas of Illinois: Illinois has a variety of protected areas, including 123 state protected areas - state parks, wildlife areas, recreation areas, nature reserves, and state forests.  There are also federal and local level protected areas in the state.  These levels interact to provide a variety of recreation opportunities and conservation schemes, sometimes in a small area.  For instance, 1500 acre Shabbona Lake State Park lies in DeKalb County which has its own 1000 acre forest preserve system, while the city of DeKalb has a 700 acre park system.  There is one UNESCO World Heritage Site in Illinois, Cahokia.

Bear Brook murders: The Bear Brook murders (also referred to as the Allenstown Four) are four unidentified female murder victims discovered in 1985 and 2000 at Bear Brook State Park in Allenstown, New Hampshire.  All of the victims were either partially or completely skeletonized; they are believed to have died between 1977 and 1985.

Supporting paragraphs: Bear Brook murders Bear Brook State Park
Answer: four