I will be with my wife in Michigan during the fall for a couple of weeks. What is there to do for people who love nature/the outdoors? We're fairly active people who are touching down in Grand Rapids, but open to driving around the state.
Michigan is beautiful in the fall with the changing leaves. www.Michigan.org has a great color map and a good interactive map for visiting. I would suggest heading up to Traverse City and/or Sleeping Bear Dunes. That area has lots of good wineries.