After passing under Boundary Avenue, the Bethpage Parkway bends to the northwest, leaving the Massapequa Preserve but continuing to run across a wooded strip of land in an otherwise heavily developed area. The highway passes through South Farmingdale on its way into the Farmingdale section of Oyster Bay, where it briefly widens to four lanes and begins to curve northward ahead of exit B3, a partial cloverleaf interchange with NY 24 (Hempstead Turnpike). The southbound cloverleaf ramps connect directly to NY 24, while the northbound ramps use a short section of Beach Street to reach the state route. Continuing northward, the Bethpage State Parkway passes under the Main Line of the Long Island Rail Road tracks and enters Bethpage, where the highway meets Central Avenue at exit B4 just north of the tracks.