It is my understanding that way back when the idea of shipping rail cars across the Straits of Mackinaw first came about, various plans were studied, including bridging the straits by jumping from mainland to several of the small islands up there to complete a land to land crossing. But that plan never got off the ground as far as I know. As for the Mackinaw bridge, I think it was considered in the early stages of planning, but was scrapped for reasons I don't know...maybe cost being the most relevant. Anyway, keep in mind, the bridge was opened by 1958, and the existing car ferry (Chief Wawatam) was operating pretty steady at that time. Rail ferry service continued until around 1984, when dwindling car counts and the expense of keeping the Chief running killed the service. Will there ever be any return to cross lake traffic at Mackinaw? It would be beyond anyone's imagination why any rail company would relay rail from Petoskey or Gaylord on the lower penninsula, and Trout Lake to St Ignace on the upper side and have a new multi-million car ferry built for the reason of transporting any kind of material between the two halves of Michigan. As much as I would like to side with such adventure, I would have to say that Trucks have won this fight hands down.