Other cities served by these area codes include Ada , Ashland , Bellevue , Bluffton , Bowling Green , Bryan , Bucyrus , Celina , Clyde , Crestline , Defiance , Delphos , Edison , Erastus , Findlay , Fostoria , Fremont , Galion , Kenton , Lima , Mansfield , Mount Gilead , Napoleon , Norwalk , Oak Harbor , Port Clinton , Sandusky , Shelby , St. Marys , Tiffin , Upper Sandusky , Van Wert , Wapakoneta , Wauseon , Willard .