Just ten days ago these scenes were typical of area rural roads around 42N country. I was going to use the intro, "You know you are in Iowa when you see..." but I'm guessing this happens all around the northern US and Canada while the weather is still good. What I observed on this day was a combination of corn harvest and distribution plus some field preparation for next season.
Obviously when tooling around in your latest version of the Model A, be on the lookout for these giant field machines. Sometimes a caravan of vehicles accompany these slow movers from one field to another. Usually the slow moving tractors don't travel long distances and will try to help you navigate around them. Field preparation and harvest season may be finished for the season with many fields cleared and snowy weather predicted soon. Know that.