The Agate museum in Grand Marais MI is pretty cool but the one to visit is the Shipwreck museum at Whitefish point.
http://www.shipwreckmuseum.com/whitefish-point-4/
That really is a great place to visit.
The museum is fascinating.Graveyard of the lakes.
Toured the museum to the music of Gordon Lghtfoot .
We spent about two hrs in there.
Love Michigan...in the summer.