I have canoed to the park before. There is a long shoals area north of the park. Be prepared to walk a lot and carry or drag your canoe behind you for a long time. It is fun though. I would do it again. Just take plenty of breaks and enjoy the scenery. You will most likely see a bald eagle or two.
There was an article in one of the lake magazines o couple of years ago about a guy who did the hole river. I think he wrote a book about it. You should find the article or buy the book