Food between MSP to Rapids City
Al's Oasis in Chamberlin, SD is a popular spot for basic, home style food. Chamberlin is really the gateway to western South Dakota and the scenery changes quite dramatically as you cross the Missouri River, very pretty. Al's is on the eastern side though, before you cross. It's kind of a touristy joint with lots of trinkets and such but the food is good. They make several kinds of pies which go well with their coffee.