Trip help, thumb area Michigan

[TripleJ]

 I'm going to be rolling north from the Port Huron area tomorrow (Saturday).  I'm wondering if anybody here has any favorite spots in Michigan's thumb.

My intention is to scope the campgrounds and attractions, find some go-to's that are relatively close to home.  I have two kids in the single digits, but we're not really looking for the KOA type places, just quiet, scenic, interesting, educational(?)...
Any input is appreciated

JC