Hi again! For some reason I couldn't send my whole message,so here are some more ideas. 8 > )
Quilt shops will usually have flyers in their windows or on their counter for upcoming quilt shows.
I have never been able to find all the shows listed in one place. Some of the smaller shows may not be posted on the internet. During my search for the Twin Cities, I wrote down all the information I found and kept it in a folder. I also kept quilt show flyers in the folder because quilt guilds have a tendency to have their shows at about the same time each year or every other year. Before traveling too far, I suggest you call and double check about the times and dates.
I frequently heard there is a large Ann Arbor guild that puts on a great show. I don't have any details though.
While happily surfing the net, I also found a list of Michigan quilt guilds.
http://www.quiltguilds.com/michigan.htm
On the left side of the page, there is a link to "shows listed by month". There are shows listed for other states, but some may show up for Michigan.
Enjoy the shows!