When the railroad was build between 1853-1860 by the Dubuque & Pacific Railroad, they didn't worry too much about the lay of the land. The railroad was pretty much built right over it as it layed. Later on the changes were made to help the steep grades. Around Winthrop some of the steeps grades existed, as seen here the nooks and crannies are pretty crazy. The ADM shuttle train hammers as they start upgrade around the 40-45 mph. In the next mile the train's momentum will bong down and the pull will be on to get over this grade at only 25 mph. Down hill fast, up hill slow, normal operations on the Dubuque Sub.