ROAD TRIP! - from Chicago to Denver - Midwest Musts?

Greetings,

My husband and I are about to take a LONG drive to Denver to visit my sister. We're going to take our time and enjoy what we hope will be a good road trip.(have not had one really since college, oh and yes we're doing this in part to celebrate our 13th wedding anniversary, July 4th!)

Need help/suggestions with must see/dine spots from here to there. We're willing to detour if the grub is good and the scenery "interesting". In true chowhound style - we're Ritz to Rags - the food's the thing!

Have not chosen a route yet. Plan to go out one way and back another though. Leaving June 29, plan to arrive Denver about July 1. And back the 7,8,9 July.

Happy to reciprocate with info on Chicago if you need it.

TIA,

Kristene