| Owner | Manager | From | Until | | Western Transit Company - Buffalo, New York | | 1905/09/15 | 1916/02/22 |
| Great Lakes Transit Corporation Inc. - Buffalo, New York | | 1916/02/22 | 1930 |
| Great Lakes Transit Corporation - Midland, Ontario | James Playfair | 1930 | 1931 |
| Midland Steamships Ltd. - Midland, Ontario | | 1931 | 1938 |
| Upper Lakes & St. Lawrence Transportation Company Ltd. - Toronto, Ontario | | 1938 | 1959 |
| Upper Lakes Shipping Ltd. - Toronto, Ontario | | 1959 | 1964 |
| Toronto Harbor | | 1964 | 1966 |
| United Steel & Refining Company - Hamilton, Ontario | | 1966 | Scrapped |
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| Fleet | From | Until | | Great Lakes Transportation Company - Midland, Ontario | 1930 | 1931 |
| Midland Steamship Lines, Inc. | 1931 | 1938 |
| Upper Lakes & St. Lawrence Transportation Company - Toronto, Ontario | 1938 | 1959 |
| Upper Lakes Shipping Ltd. (ULS) - Toronto, Ontario | 1959 | 1964 |
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