Ottawa River

Ottawa River, the largest tributary of the St. Lawrence, and one of the largest Canadian rivers, is 700 m. long; rising in the W. of Quebec, it flows W., then S., then SE., sometimes in a narrow channel, sometimes broadening even into lakes, receiving many tributaries, and passing down rapids and falls, and joins the St. Lawrence at Montreal; down its waters are floated immense quantities of lumber.

Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)

Ottawa * Otterburn
[wait for the fun]
Oswald, St.
Oswego
Oswestry
Otago
Othman
Othman
Otho
Otis, James
Otranto
Ottawa
Ottawa River
Otterburn
Otto
Ottomans
Otway, Thomas
Oubliette
Oudenarde
Oudh
Oudinot, Duke of Reggio
Ouida
Ouse