 The major tributaries are the Diveria, Bogna, Melezzo Occidentale (joining it near Domodossola), Ovesca, Anza (near Piedimulera), and the Strona (near Gravellona Toce).In ancient times the Toce river was called Athisone or Atisone, from which the current name is derived.An old alternative spelling is also La Toccia (with feminine gender).