Watertown and Brownville NY 12E begins at the intersection of West Main and Bradley (
NY 12) streets in the city of
Watertown. It initially proceeds northwest on West Main Street as a four-lane residential and commercial street; however, it becomes a two-lane divided highway at a
CSX Transportation railroad overpass just six blocks from NY 12. Past the crossing, the road follows the
Black River across the city line and into the town of
Pamelia, where it becomes
co-designated as CR 190. The highway soon passes under
Interstate 81 and narrows to a two-lane undivided road before turning westward into the riverside village of
Glen Park. It retains its Main Street name through the community, following a two-lane residential street through the village center and eventually into the adjacent
village of Brownville. In Brownville, the route intersects with the northern terminus of Bridge Street (unsigned NY 971H), a short north–south connector leading to
NY 12F on the south bank of the Black River. At this point, the CR 190 co-designation ends and maintenance of the route becomes the responsibility of the state. Through Brownville, NY 12E remains a two-lane residential and commercial street, intersecting with the southern terminus of
CR 54 (Brown Boulevard) near the
Brownville Hotel, a
National Register of Historic Places-listed (NRHP) property. At the western edge of the village, NY 12E passes Brownville Cemetery before leaving for the surrounding
town of Brownville and losing the Main Street name. The highway parallels a former railroad right-of-way as it heads through the town of Brownville, becoming a two-lane rural highway and gradually bending northeastward away from the riverbank. NY 12E leaves Limerick after this junction and continues through the town of Brownville, bending slightly to the northeast at a junction with
CR 59 (North Shore Road) from Limerick at the Brownville–
Lyme town line. Just past the district, the route intersects with
CR 179 (Evans Street), After this junction, NY 12E crosses over the
Chaumont River and leaves the village limits at a junction with
CR 8 (Johnny Cake Road). on its way to the south bank of the St. Lawrence River. Here, it intersects with Broadway, an east–west village street connecting to
CR 6 west of the village. NY 12E turns northeastward on Broadway, passing through the
Broadway Historic District and serving the NRHP-listed
Vincent LeRay House. Two blocks from Market Street, NY 12E intersects with James Street, which leads to
Wolfe Island via
Horne's Ferry. Past James Street, NY 12E follows Broadway through a commercial area that continues to the eastern village limits.
St. Lawrence River corridor Outside of the village of Cape Vincent, NY 12E loses the Broadway moniker, passing St. Vincent of Paul Cemetery and a mobile home park as it runs northeastward along the St. Lawrence River. About from the village, the route passes an intersection with Carleton Drive, which serves a ferry linking
Carleton Island to the river's south bank. After Carleton Drive, the route continues northeast through the town of Cape Vincent, passing another mobile home park and
Burnham Point State Park. The route continues on, entering the adjacent hamlets of Sunnybank and Millins Bay. In the latter, NY 12E intersects with
CR 7, a riverside highway serving a small community located between the river and NY 12E. At the northern end of Millins Bay, CR 7 merges back into NY 12E, and the latter highway continues along the St. Lawrence River through the northern reaches of the town. Not far from the eastern town line, the route intersects with
CR 9 (Sand Bay Road) and passes the
Cape Vincent Correctional Facility and
Cedar Point State Park, located on opposite sides of the highway. After the correctional facility, NY 12E crosses into the
town of Clayton, where the route remains a two-lane rural riverside highway. Roughly into the town, the route bends slightly to the east and intersects with the northern terminus of CR 4 (Fish Pond Road), which intersected NY 12E back in the town of Cape Vincent. Past the junction with CR 4, NY 12E bends back to the northeast, passing more riverside residences and a handful of farms before entering the
village of Clayton. In the village, NY 12E becomes known as State Street as it crosses over an inlet from the St. Lawrence River. The bridge over the waterway brings the route into Clayton's downtown portion, where it intersects with NY 12 (James Street). This intersection serves as the northern terminus of NY 12E, as State Street continues northeastward as part of NY 12. ==History==