Brooklyn Michigan campgrounds

So as part of heading North during the summer, we are going to swing up though Michigan and attend the NASCAR event at Michigan Speedway with some friends. Once we are done with the event we were thinking of heading North to the Mackinac Island area and Hiawath Forest. We don’t have any restrictions on dates so anything else we should explore while we are in the area?

We like places like museums and historical sites and national historic sites. Anything that is a must while visiting?

@Farva have you looked at Google maps?