O. Bedell
O. Groh
O. H. Brown
O. Newberry
O. Novella
O. W. Blodgett
O/Y Merviente
Ogdensburg & Prescott Ferry Co. Ltd.
Oglebay-Norton Co., Cleveland, Ohio
Ohio-Michigan Navigation Co.
Old Dominion Line
Oldrieve & Co.
Oliver J. Olson Lumber Co.
Olson
Ontario Transportation and Pulp Co.
Osborne Material Co., Cleveland, Ohio
Ottawa River Navigation Co.
Overlakes Freight Corporation
Owen Sound Transportation Co.