Organized rides in Indiana & Michigan

I would like suggestions of good organized rides in Southern Michigan
and upper Eastern part of Indiana area. The rides should be in July,
August or September. I would like the rides to include at least 20
through 50 miles, have good participation and be a good value (well
organized, on uncrowded roads and decent food). I don't want to just
contribute to a ride that is organized for the sponser of a cause
only. What suggestions can you give?