We plan to drive US 31 from northern Indiana on our way to Traverse City. (On subsequent days, we will see Sleeping Bear Dunes and the surrounding area.) My question here is regarding good stops along the drive north. I like beaches and lighthouses, and I'd like to stop to see some. Unfortunately, the Michigan website is not clear about fees for state parks, and some of the lighthouses appear to be in state parks. Since we won't be making long stops, I don't really want to pay multiple park fees unless it's worthwhile. I'd like some advice about which beaches and lighthouses to see and what fees to expect.