Question: Where in New York is the highway that ends at the toll barrier for Heckscher State Park in Great River?

full_context: Document 1: Grand Central Parkway: The Grand Central Parkway (GCP) is a 14.61-mile (23.51 km) long parkway that stretches from the Triborough Bridge in New York City to Nassau County on Long Island. At the Queens–Nassau border, it becomes the Northern State Parkway, which runs across the northern part of Long Island through Nassau County and into Suffolk County, where it ends in Hauppauge. The westernmost stretch (from the Triborough Bridge to exit 4) also carries a short stretch of Interstate 278 (I-278). The parkway runs through Queens and passes the Cross Island Parkway, Long Island Expressway, LaGuardia Airport and Citi Field, home of the New York Mets. The parkway is designated New York State Route 907M (NY 907M), an unsigned reference route. Despite its name, the Grand Central Parkway was not named after Grand Central Terminal.
Document 2: Southern State Parkway: The Southern State Parkway (also known as the Southern State or Southern Parkway) is a 25.53 mi limited-access highway on Long Island, New York, in the United States. The parkway begins at an interchange with the Belt and Cross Island parkways in Elmont, in Nassau County, and travels east to an interchange with the Sagtikos State Parkway in West Islip, Suffolk County, where it becomes the Heckscher State Parkway. The Southern State Parkway comprises the western portion of unsigned New York State Route 908M (NY 908M), with the Heckscher Parkway occupying the eastern section.
Document 3: Sagtikos State Parkway: The Sagtikos State Parkway, also known as the Sagtikos or Sagtikos Parkway, known colloquially as "the Sag" is a 5.14 mi north–south limited-access parkway in Suffolk County on Long Island, New York, in the United States. It begins at an interchange with the Southern and Heckscher state parkways in the hamlet of West Islip and goes north to a large cloverleaf interchange with the Northern State Parkway in the town of Smithtown, where the Sagtikos ends and the road becomes the Sunken Meadow State Parkway. The parkway comprises the southern half of New York State Route 908K (NY 908K), an unsigned reference route, with the Sunken Meadow State Parkway forming the northern portion. Commercial vehicles are prohibited from using the Sagtikos State Parkway, a restriction that applies to most parkways in the state.
Document 4: Cherry Grove, New York: Cherry Grove (often referred to locally as The Grove) is a hamlet in the Town of Brookhaven, Suffolk County, New York, United States. It is located on Fire Island, a barrier island separated from the southern side of Long Island by the Great South Bay. The hamlet has approximately 300 houses on 41 acre , a summer seasonal population of 2,000 and a year-round population of 15.
Document 5: Northern State Parkway: The Northern State Parkway (also known as the Northern State or Northern Parkway) is a 28.88 mi limited-access state parkway on Long Island in the U.S. state of New York. The western terminus is at the Queens–Nassau County line, where the parkway continues westward into New York City as the Grand Central Parkway. The eastern terminus is at New York State Route 347 (NY 347) and NY 454 in Hauppauge. The parkway is designated New York State Route 908G (NY 908G), an unsigned reference route. As its name implies, the parkway services communities along the northern half of the island.
Document 6: Heckscher State Parkway: The Heckscher State Parkway (formerly known as the Heckscher Spur) is an 8.24 mi parkway on Long Island, New York, in the United States. The parkway, located entirely within the Suffolk County town of Islip, begins at the south end of the Sagtikos State Parkway in West Islip, from where it continues west as the Southern State Parkway. It proceeds east as a six-lane parkway through Brentwood and Central Islip, loosely paralleling New York State Route 27 (NY 27). At Islip Terrace, the Heckscher Parkway turns southward, crossing NY 27 before ending at the toll barrier for Heckscher State Park in Great River. The parkway comprises the eastern portion of New York State Route 908M (NY 908M), an unsigned reference route, with the Southern State Parkway occupying the western section. In order to avoid confusion, the highway is signed as an extension of the Southern State Parkway west of the NY 27 interchange (exit 44).
Document 7: Long Island: The Long Island is a large, densely-populated island off the East Coast of the United States, beginning at New York Harbor just 0.35 miles (0.56 km) from Manhattan Island and extending eastward into the Atlantic Ocean. The island comprises four counties in the U.S. state of New York: Kings and Queens (which comprise the New York City boroughs of Brooklyn and Queens, respectively) to the west; and Nassau and Suffolk to the east. However, many people in the New York metropolitan area (even those living in Brooklyn and Queens) colloquially use the term "Long Island" (or "The Island") exclusively to refer to the Nassau–Suffolk county area collectively, which is mainly suburban in character. The majority of New York City residents now live on Long Island.
Document 8: Outer barrier: The outer barrier, also known as the Long Island and New York City barrier islands, refers to the string of barrier islands that divide the lagoons south of Long Island, New York from the Atlantic Ocean. These islands include Coney Island, Long Beach Barrier Island, Island Park, Jones Beach Island, Fire Island and Westhampton Island. The outer barrier extends 75 mi along the South Shore of Long Island, from Rockaway Beach on the New York City/Nassau County border from Long Beach Barrier Islands' western edge, to Suffolk County's east end of Shinnecock Bay.
Document 9: Bay Shore, New York: Bay Shore is a hamlet and census-designated place (CDP) in the Town of Islip, Suffolk County, New York, United States. It is situated on the South Shore of Long Island, adjoining the Great South Bay. In 2008, Bay Shore celebrated the 300th anniversary of the purchase of the land from the Secatogue Native Americans. The population of the CDP was 26,337 at the time of the 2010 census.
Document 10: Great River, New York: Great River, New York is a suburban hamlet and CDP in the Town of Islip, Suffolk, USA situated approximately 50 mi (55 mi driving) east of NYC on South Shore of L.I., adjoining the Great South Bay, protected from the Atlantic Ocean by Fire Island.
Document 11: South Shore Estuary: The South Shore Estuary is an estuary located along the south shore of Long Island, between the mainland and the outer barrier islands, in eastern New York state. It stretches for over 70 mi from West Bay in Nassau County to the Shinnecock Bay in Suffolk County.
Document 12: Fire Island: Fire Island is the large center island of the outer barrier islands parallel to the south shore of Long Island, New York. In 2012, Hurricane Sandy once again divided Fire Island into two islands. Together, these two islands are approximately 31 mi long and vary between 160 and wide. Fire Island is part of Suffolk County. It lies within the towns of Babylon, Islip, and Brookhaven, containing two villages and a number of hamlets. All parts of the island not within village limits are part of the Fire Island census-designated place (CDP), which had a permanent population of 292 at the 2010 census, though that expands to thousands of residents and tourists during the summer months.
Document 13: Great South Bay Bridge: The Great South Bay Bridge is a bridge on the southwest side of Suffolk County, New York, on Long Island. It connects the Robert Moses Causeway from Long Island's mainland over the Great South Bay, connecting to both Captree and Jones Beach Island. It serves as access via the Robert Moses Causeway to both of the downstream crossings, the State Boat Channel Bridge and the Fire Island Inlet Bridge, also leading visitors and on-lookers to either the Fire Island Lighthouse or the Robert Moses State Park. It is the second longest bridge in the New York State, behind only the Tappan Zee Bridge.
Document 14: Heckscher State Park: Heckscher State Park is a 1657 acre state park on the shore of the Great South Bay at East Islip in Suffolk County, New York, USA.
Document 15: Henry Hudson Parkway: The Henry Hudson Parkway is an 11.05 mi parkway in New York City. The southern terminus is at West 72nd Street in Manhattan, where the parkway continues south as the West Side Highway. It is often erroneously referred to as the West Side Highway throughout its entire course in Manhattan. The northern terminus is at the Bronx–Westchester county boundary, where it continues north as the Saw Mill River Parkway. All but the northernmost mile of the road is co-signed as New York State Route 9A (NY 9A). In addition, the entirety of the parkway is designated New York State Route 907V (NY 907V), an unsigned reference route.
ground_truth: Long Island, New York