The Great Lakes/St. Lawrence Seaway was built as a binational partnership between the U.S. and Canada, and continues to operate as such.
Administration of the system is shared by two entities, the Saint Lawrence Seaway Development Corp. in the U.S., a federal agency within the U.S. Department of Transportation, and The St. Lawrence Seaway Management Corporation in Canada, a not-for-profit corporation (ownership of the Canadian portion of the Seaway remains with the Canadian federal government.)