The route winds along the bank of river to the hamlet of Warrensburg, where the route becomes River Street and heads past several blocks of houses. At Alden Avenue, the route curves to the northeast, mirroring the curvature of the river through Warrensburg.
It continues along the waterway to the junction of Ridge and River Streets, where NY 418 turns north onto Richards Avenue and finally crosses the river on a truss bridge. The route meets Water Street (CR 9) on the opposite bank before continuing northward past several commercial properties to the center of Warrensburg, where NY 418 ends at an intersection with US 9 (Main Street).