Midway between Natural Bridge and Harrisville, NY 3 intersects NY 812. NY 812 turns east onto NY 3, following NY 3 northeast into St. Lawrence County before splitting to the northwest between Harrisville and Pitcairn. Shortly after departing NY 812, NY 3 enters Adirondack Park. The route follows a largely east–west routing from its entry point to Tupper Lake, where it merges with NY 30. Near Upper Saranac Lake, NY 30 heads north toward Malone as NY 3 continues northeast through nearby Saranac Lake toward Plattsburgh.