GoWaterfalling’s entry for Interstate Falls/Peterson Falls says (in part):
This waterfall is located on the Montreal River just a few miles upstream of Saxon Falls. The Montreal River forms part of the border between Michigan and Wisconsin so the falls is technically in both states, and can be visited from either state, but it is most easily visited from the Wisconsin side.
There seems to be some confusion about what this waterfall is named, or at least I am confused. Some sources refer to this as Peterson Falls, and the sign on the highway says “Peterson Falls”. However others say that this falls is Interstate Falls and that Peterson Falls is a smaller waterfall upstream of Interstate Falls. I have decided to go with Peterson Falls until I learn otherwise.
Read on for directions & more info.