There's a really cool city park in Winterset, Iowa. It's not too far off of 35N just south of Des Moines. John Wayne's childhood home is there (very close to the park entrance), and the city park has a maze made out of shrubs with a sundial in the center. There are very nice areas for a picnic lunch, and pretty little stone bridges over a creek that runs through the park. In the back part of the park is a pretty stone tower with a wonderful view. It was erected in memory of some early settlers in the area. It's worth stopping there if you have time.
There are some really pretty covered bridges on the way to Winterset (bridges of Madison County...) One of them has a bunch of graffiti from many visitors over the years. There's a little notice that someone had written that there are 9 "ninjas" hiding on the bridge. These are about 2 inches high, and were drawn with a black sharpie. All of them are slightly different. My son and I stopped once to see the bridge, and stayed for an hour to find all 9 "ninjas". We took a picture of each to make sure we didn't miss any. There's also a neat military museum in Des Moines, and a glass pedestrian bridge. Lots of cool things to see in Iowa along that route! Enjoy the trip, and if you see anything worth stopping for, please let us know. I'm sure we'll be through that way again.
I find most things were 
The last time I was there, everything got shut down due to lightening. 
