Rob_E

But that doesn't get them to the Catawba area unless they use the bridge to cross Sandusky Bay. The part I was missing was that they also wanted to go to Vermillion, which is east of everything else, "on the way" to Detroit, which basically requires going northwest from Fremont. With the Vermillion stop in mind, I think I'd start this trip by going from Fremont to Vermillion, maybe using the Inland North Coast Trail, such as it is, to get south of Vermillion, then travel north to town (to whatever they wanted to see in Vermillion). Then go west along the coast into Sandusky, catch a Jet Express ferry to Put-In-Bay, bike to the car ferry port on South Bass, and take the Miller Boat Line to Catawba. From there continue on towards Detroit.

The problem with going between Catawba and Vermillion is you have to go over or around Sandusky Bay. The problem with doing Catawba first, then Vermillion, then Detroit is that you have to deal with the bay twice. And if you try and go around the Bay to the south, you basically end up back in Fremont to cross the Sandusky River. Assuming the OP is based out of Fremont, they might as well do a mini tour to Vermillion as a separate trip if they can't find a better way across the bay.