Lots of places to see and take some time. St. Louis Gateway Arch, St. Louis Grant's Farm, Hannibal, MO, home of Mark Twain, Truman Library, Ft. Hays, KS, Denver. On the way back you could go to Yellowstone, Grand Tetons, Buffalo Bill Museum in Cody, WY, Devil's Tower, Black Hills Mt. Rushmore & Crazy Horse Momument & Indian Museum, and on and on. It's according to what interests you, Google "<State name> places of interest" to find lot's of info.
Bob & Donna
'98 Gulf Stream Sun Voyager DP being pushed by a '00 Beetle TDI