I have done several tours in the area and linking them together I would suggest if time is not a issue, starting in Green Bay and follow the Lake Michigan coast North East, cross the Mackinaw straight using the ferry to Mackinac Island (possibly staying a night on the island). Follow the Lake Huron Shore down through Bay City, head due east across the thumb, I used Deckerville RD. South along the lake shore and along the St Clair River, crossing to Canada at the Marine City ferry. Heading South East near Rondeau Park and then following Lake Erie shore thru Port Colborne. At this point either heading North along the Welland Canal (nice paved bike path) to Thorold and then Niagara Falls, or keeping with Lake Erie and catching the Friendship trail (paved bike rail trail) to Ft Erie and then following the Niagara River to Niagara Falls.
You could also head North after St Ignace and cross into Canada at Sault Ste Marie heading towards Manitoulin Island. I did a tour this summer from Sudbury thru Manitoulin Island, along Lake Huron back to Niagara Falls, but I have no experience from Sault Ste Marie to Espanola other then some planning and remember that there is only 1 road and very desolate area.
A shorter route would be to take the Ferry from Manitowoc to Ludington and cross Michigian to Bay City, (I haven't done this).
Jeff
