At the junction with Old Plank Road, PA 646 turns for the south while PA 346 continues east and northeast into Otto Township. After a bend to the southeast, the route reaches the village of Duke Center, where it reaches the southern terminus of PA 546. Running southeast from PA 546, PA 346 starts paralleling PA 246 before the two roads intersect in Otto Township. After PA 246, the route turns northeast once again and crosses into the borough of Eldred. In Eldred, PA 346 passes over the Allegheny River and the Buffalo Line railroad line, which is owned by Norfolk Southern and operated by the Western New York and Pennsylvania Railroad, before it ends at an intersection with PA 446.