In Buffalo, the Seaway Trail leaves Route 5 for good as it heads north through downtown. It soon picks up NY 266 and follows it to the tip of Lake Erie. Now paralleling the Niagara River, going north, the trail follows Route 266 through the town of Tonawanda and into the city of Tonawanda, a Buffalo suburb. Just before crossing Tonawanda Creek, which forms the county line, Route 266 ends and the Seaway Trail picks up NY 265 to cross the creek and the border.