That's the challenge of the annual RAIN (Ride Across Indiana) event on July 12, 2008. The ride goes west to east across the state through (mostly) rural rolling-to-flat landscapes. The event starts at 7:00 a.m. in Terre Haute and officially ends at 9:00 p.m. (sundown). Usually, the prevailing winds will be at your back.
There are three rest stops and a lunch stop. You can set up your own sag support or sign up with a service that will take care of you and haul your tired butt back to the starting line. More info here:
I'm not sure I'm going to go for it, but I'm tempted. I do think it would be great to have a BF 50+ contingent on the route.