New York State Route 9J (NY 9J) is a north–south state highway in the Hudson Valley region of New York in the United States. It begins at an intersection with US 9 in the Columbia County town of Stockport and extends for to an interchange with US 9 and US 20 in the Rensselaer County city of Rensselaer. The route parallels the Hudson River for its entire length, and several parts of the highway run directly alongside the river. NY 9J was assigned to its current alignment as part of the 1930 renumbering of state highways in New York. Route description NY 9J begins at an intersection with US 9 in the hamlet of Columbiaville, located within the town of Stockport. The route proceeds northwest along a two-rural street that parallels US 9 until the intersection with Day Road, where it turns westward. Reaching the Amtrak and Norfolk Southern's Hudson Subdivision, NY 9J and the tracks begin a northward trek near the Hudson River, winding past a junction with County Route 46 (CR 46) in the town of Stuyvesant. Winding northward along the tracks, NY 9J reaches the hamlet of Stuyvesant, where it intersects with CR 26A (Kinderhook Street), a highway formerly designated as NY 398. NY 9J continues north out of the hamlet of Stuyvesant, paralleling, crossing then paralleling a spur of the railroad tracks north of town. Retaining its northerly direction, the route parallels the Muitzes Kill and past Schodack Island State Park (composed of what was six islands now reduced to two). A short distance northward, NY 9J crosses into Rensselaer County and enters the town of Schodack. Immediately entering the hamlet of Schodack Landing, the route remains a two-lane residential street, crossing a junction with the western terminus of CR 2 (Schodack Landing Road). Just after crossing the intersection with Knickerboxer Road, NY 9J crosses under the New York State Thruway's Berkshire Thruway and the Castleton-on-Hudson Bridge. Past the Thruway crossing, NY 9J turns northeast, crossing Muitzes Kill and intersecting CR 1 (Muitzes Kill Road) on the river's north bank. At this point, the road becomes known as South Main Street as bends northward into the village of Castleton-on-Hudson. Crossing north through the village, NY 9J parallels the Norfolk Southern tracks to an intersection with the western terminus of NY 150 (Scott Avenue). The route continues through Castleton-on-Hudson's northern portion as North Main Street before leaving