I'll step up and coordinate the Southwest Michigan region. Area codes 269 & 616, roughly speaking. This would be Kalamazoo, Grand Rapids, Battle Creek - all points between Lake Michigan and I-69, South of Grand Rapids and North of the Michigan/Indiana line. If you are in this region and want to join the ride and/or have ideas on routes and landmarks, send me a PM!
Whoever would like to claim Northern Indiana, Southeast Michigan and/or Northern Lower Peninsula, send me a PM and we can talk about places for a hand off!