If you are traveling through Gaylord, stop and see the elk. One of the viewing areas is east of BR I-75 on Grandview Blvd. We stopped the Friday of Memorial Day weekend just before dusk and saw about 30-40 elk. Some of the bulls already have good sized antlers.
Gaylord ElkIf you had time, with the winter we had I bet now would be a great time to see elk in the wild in the Pigeon River Forest.
Parrothead Mike mentioned Indian Lake just west of Manistique. Nearby is Kitch-iti-kipi, or the Big Spring at Palms Book State Park. It is a large spring feed pond/lake that you can take a raft out onto and look to the bottom of the pond. You probably can't kayak it, but it is cool to see.
Palms Book SPIf you take the suggestions to go to Whitefish Point, you might as well visit Tahquamenon Falls while you are right there. The kids enjoyed it so much last summer we took a road trip in February (2 weeks after #5 was born) to see it almost frozen over. There are hiking trails that connect the upper and lower falls.