In Williamsville, NY 277 remains a four-lane residential boulevard, crossing a junction with NY 5 (Main Street). At this junction, NY 277 becomes known as North Union Road, reducing to two lanes as it passes more residences in Williamsville. Just north of North Forest Park, the route turns northwest and returns to the town of Amherst. Now known as North Forest Road, the route winds northwest past multiple residences before reaching a junction with NY 324 (Sheridan Drive). The junction with NY 324 marks the northern terminus of NY 277, while North Forest Road continues north as CR 294 past Westwood Country Club.