North of the industrial zone in East Farmingdale, Republic Road regains the designation of CR 28 at the Babylon/Huntington town line.

The road serves as a connection between Westhampton Beach and the Riverhead area, feeding directly into CR 104 as it makes its way north.

Heading north, this arrow-straight portion of the road crosses the Long Island Rail Road's Montauk Branch railroad tracks and then runs through the grounds of Francis S. Gabreski Airport, a former base of the United States Air Force, which is now home to the 106th Rescue Wing of the New York Air National Guard.

The route used to be designated north of the bridge along Lighthouse Road, Foster Avenue, Shinnecock Road, and Ponquogue Avenue to Montauk Highway in Hampton Bays, but neither the Suffolk County Department of Public Works or the New York State Department of Transportation recognize that portion of the roadway as CR 32, just the Ponquogue Bridge portion.

It was a former segment of CR 35 that was established in 1970 when the New York State Department of Transportation created (what was intended to be) a temporary alignment of NY 231.

[3] Outside of the village limits, CR 34 crosses over New York State Route 27 (Sunrise Highway) as part of Exit 40, which is primarily for NY 231 to the east.

Continuing northwest, CR 35 has an at-grade crossing with the Port Jefferson Branch of the Long Island Rail Road, which has been the site of many tractor-trailer accidents, and was the original location for the first "Low Ground Clearance" warning sign.

Well past the intersection of Bellhaven Avenue, the road begins to turn north as it follows the west bank of Beaver Dam Creek, which is hidden off to the east.

Until the late 1980s, flood insurance maps published by the Federal Emergency Management Agency have misrepresented South Country Road as being NY 95.

The route's mileage and designation is only recognized by the SCDPW or by the New York State Department of Transportation between Southampton Village and North Sea.

[3] As far back as the 1930s the road was planned to be extended along the north shore of the South Fork of Long Island to the Amagansett–Promised Land area.

The CR 38 extension would gradually move southeast again, running along the headwaters of Northwest Creek and Three Mile Harbor, through Barnes Hole, and Devon until reaching Promised Land Road (former CR 33), which it would replace until it reached NY 27 (Montauk Point State Parkway) in the East Hampton Beach section of Napeague.

Most of the road is concurrent with NY 27, where it is known as the Southampton Bypass, except for the portion along the Shinnecock Canal and the Great Peconic Bay.

The road runs beneath the Sunrise Highway (NY 27) bridge over the Canal, just as CR 39 does, and provides closer access to Meschutt Beach County Park.

It heads north-northeast from Downtown Riverhead towards the North Shore of Long Island, ending at Sound Avenue in the hamlet of Northville, New York.

County Route 43 begins at Roanoke Avenue (CR 73) just north of its crossing with the Long Island Rail Road Main Line tracks.

CR 45 intersected at Neck Path again east of the former hamlet of Kingstown, but this time it merges with the former route and then immediately turns onto Accabonac Road.

In front of the church, Springs–Amagansett Road/Old Stone Highway curves to the right, until it reaches a wye at Springs–Fireplace Road, thus serving as the former northern terminus of CR 41.

County Route 46A was the original designation for the alignment along the west side of Brookhaven National Laboratory between Yaphank–Moriches Road and south of the unnumbered interchange with NY 25.

There, the route becomes a commercial strip, especially as it approaches CR 12 (Oak Street), which once carried a streetcar line between Amityville and Babylon.

Scattered commercial operations can be found near the intersection with CR 2 (Dixon Avenue) which spans from Amityville to Dix Hills, but, for the most part, the road remains primarily residential.

As the road runs along the west side of Copiague Middle School, it approaches the cloverleaf interchange with NY 27, where CR 47 becomes a two-lane divided highway.

Prior to reaching the intersection of NY 110, CR 47 runs over the Southern State Parkway and a former gas station that existed in the median until 1985.

It starts along the east side of Fort Pond Bay as Edgemere Street, and then onto Flamingo Avenue before reaching Montauk Station.

CR 50 begins at the intersection of New York State Route 109 in the village of Babylon, north of the Montauk Branch of the Long Island Rail Road as Park Avenue.

The route straddles northward on Deer Park Avenue for three-tenths of a mile to find its way onto Simon Street but this name doesn't carry the designation very long.

For a slightly longer distance until reaching the quarter cloverleaf interchange with New York State Route 231 (NY 231, the Babylon–Northport Expressway) on the Babylon Village–West Islip border, the road suddenly takes on the name "Union Boulevard", the street that defines CR 50.

Union Boulevard continues to carry CR 50 along the south side of the Montauk Branch of the Long Island Rail Road for the rest of its length to the hamlet of Great River.

Union Boulevard runs beneath a third limited-access road between East Islip and Great River, Heckscher State Parkway.

This was a proposed extension that was phased out during the mid-1980s, although Suffolk County Department of Public Works still lists this street as being part of CR 50.