First, thank you for taking the time to post a response. I greatly appreciate your input.
QUOTE(Jerry S. @ Jan 27 2011, 10:52 PM)

From your post, I get the impression that you want to drive to one location, stay there and enjoy the RV park and sights and attractions nearby.
Yes, for the most part. We don't mind stopping and looking at sights while enroute though.
QUOTE(Jerry S. @ Jan 27 2011, 10:52 PM)

The first area I thought of was St. Ignace/Mackinaw City, Michigan. The Mackinac Bridge connects the two towns, Macinac Island is a boat ride away, the Soo Locks are an hour north and Petoskym MI is an hour south. There are also numerous sights (Apostle Islands National Lakeshore, Keweenaw Penninsula, Picture Rocks National Lakeshore, Tahquanomen Falls, ect.) on the Upper Penninsula of Michigan that you will be near if you travel east on US 2 from Duluth. Personally, I would stop for a day (near Marqutte, MI, for example) to see some of the above sights on the way to or from St. Ignace/Mackinaw City.
I visited Mackinaw Island once before a little over 10 years ago. My memory of it is that there wasn't much to do but shop. Shopping is not even on my short list of things I want to do on vacation so that area hasn't appealed to me much. Do I have the wrong impression?
The Apostle Islands National Lakeshore, Keweenaw Penninsula, Picture Rocks National Lakeshore, Tahquanomen Falls, ect. all sound interesting though... My only concern is that last year we went to the North Shore of MN (Duluth to Grand Portage to Iron Range to Itasca S.P.) and I'm wondering if it will be too similar.
We are leaning towards Yellowstone but I'm looking for additional possibilities we may be overlooking.