Yes, I'd agree with Breitbach's. Wonderful views across the countryside.
In Mason City consider the Northwestern Staekhouse if you like old school steakhouses. Be prepared for a wait if you go at prime time. But the steak is simply amazing.
If you are picking up snacks, stop for smoked Mississippi River fish and Wisconsin cheese at Valley Fish and Cheese in Prairie du Chien.
Finally, if you want whhat I consider the iconic Iowa meal, stop at any small town tavern and get the pork tenderloin sandwich. Basically a breaded pork tenderloing the size of a frisbee.