Here's a source of Michigan waterways.
FYI: One area we have been covering is international trade routes, integrity of shipping, and energy supply lines (Enbridge System carries oil and gas through MI and its waterways that supply for E & W Canada. It's huge.
I'll post an old report over the next few days that shows our routes, issues, and areas to watch over.
I prefer the prophetic and directing our security out of the presence of God but I'm also a historian of sorts so may have beneficial information.
Great reference info - thank you