) in Valley Stream The Southern State Parkway begins at an interchange (exit 25A) with the
Belt Parkway and the
Cross Island Parkway on the
Queens and
Nassau County border in
North Valley Stream. After the interchange, the Southern State proceeds east as an eight-lane divided parkway through North Valley Stream, passing north of St. Johns Cemetery before entering exit 13S and exit 13N, which serves Central Avenue, which connects to the
Linden Boulevard that runs through Queens. Bending southeast through North Valley Stream, the parkway enters a partial diamond interchange with North Fletcher Avenue (exit 14). Running along the northern end of
Valley Stream State Park, the parkway provides a ramp designated exit 15A, which connects to the park. A short distance later, the parkway enters exit 15, which connects to Corona Avenue. Proceeding westbound, a junction is also present with Franklin Avenue (designated exit 16N). After crossing into
Malverne, the Southern State enters a
cloverleaf interchange with Hempstead Avenue (exit 17). Crossing a line for the
Long Island Rail Road, the parkway winds through Lakeview before crossing into
Hempstead Lake State Park. Crossing through the park, the parkway enters exit 18 for Eagle Avenue, where it narrows to six lanes. After crossing Hempstead Lake, the parkway enters a cloverleaf interchange with Peninsula Boulevard (exit 19). Winding north of Mercy Medical Center, the route enters
Rockville Centre, passing north of
Molloy College before entering a cloverleaf with exit 20 (Baldwin Road and Grand Avenue). The six-lane parkway makes a bend after exit 20, crossing through North Baldwin, and into exit 21 with Nassau Road. After making a large bend to the northeast and turning east, the Southern State enters exit 22, a cloverleaf interchange with the
Meadowbrook State Parkway in North Merrick. Proceeding westbound, a ramp is present to Meadowbrook Road (exit 23). Just east of that, the parkway enters exit 24S–N, a cloverleaf interchange with Merrick Avenue. These three exits span less than one mile. Winding northeast, the parkway enters an interchange with
NY 106 (North Newbridge Road). Now in
North Bellmore, exit 26 connects to South Bismark Avenue on a northeastern stretch of the parkway. Making a gradual bend eastward, the Southern State enters exit 27S–N, which is an interchange with the
Wantagh State Parkway. Just east of the Wantagh, the Southern State enters an exit with Wantagh Avenue (exit 28S–N). After a short eastern stretch through the village of North Wantagh, the parkway enters an interchange with the Seaford–Oyster Bay Expressway (
NY 135), designated as Exit 28A S–N. After the Seaford–Oyster Bay Expressway, the parkway enters an exit with Hicksville Road. Now in the town of
Oyster Bay, the Southern State Parkway exit 30, with serves North Broadway in North Massapequa. Now in Massapequa State Park, the parkway enters exit 31, which serves as the southern terminus of the
Bethpage State Parkway. Just before entering exit 32S–N, the parkway crosses into
Suffolk County and the town of
Babylon. After crossing into Suffolk County, the Southern State enters exit 32S–N, which serves
NY 110 (Broad Hollow Road). Bending northeast through Babylon, the Southern State Parkway enters exit 33, which serves
NY 109 (Farmingdale Road). Near the interchange, the parkway passes south of Republic Airport, which is connected via exit 34. Winding northeast through Babylon, the parkway enters exit 35, an interchange with
CR 3 (Wellwood Avenue). Passing south of New Montefiore Cemetery, the Southern State Parkway crosses exit 36S–N, with
CR 2 (Straight Path). After winding east through Babylon, the parkway crosses through Belmont Avenue before crossing into
Belmont Lake State Park. Within the park, the Southern State crosses into exit 38, which serves the park directly. After winding out of Belmont Lake State Park, the parkway enters an interchange with
NY 231 (the Babylon–Northport Expressway and Deer Park Avenue). Crossing south of Guggenheim Lake, the Southern State Parkway enters exit 40, which serves the northern end of the
Robert Moses Causeway. From here, the highway enters
West Islip, where it connects to Bay Shore Road at exit 41S. The westbound direction of the parkway between exit 40 and exit 41 is split into a
local-express lane setup for about . Each half of the split is two lanes wide. After the Bay Shore Road interchange is the
Sagtikos State Parkway, which is connected via exit 41A. At this interchange, the Southern State Parkway becomes the
Heckscher State Parkway, which continues east and south towards
Heckscher State Park. ==History==