West of the city of Watertown, NY 3 intersects NY 180 southwest of the Watertown International Airport before connecting to I-81 by way of an interchange at the city line. NY 3 heads east into Watertown, intersecting with both US 11 and NY 12 at Massey Street. At this point, maintenance of NY 3 shifts from the state to the city of Watertown. The route overlaps NY 12 southbound and a short piece of US 11 northbound through downtown to Public Square, where NY 3 meets northbound NY 12. US 11 northbound leaves NY 3 here while the overlap between NY 3 and NY 12 continues eastward through Watertown. The concurrency ends near the eastern fringe of the city, where NY 3 leaves NY 12 and becomes state-maintained once more as it departs the city to the northeast.