Coming up to lock number five at Minnesota City, Minn., tow boat pilot Tom Persons tells us the crew always needs to be cautious. These tow boat jobs are extremely dangerous and require special skills with an extremely high emphasis on safety.

With our tow boat and 15 barges filled with corn, wheat and soybeans now heading downstream, Captain Rider says 100 miles represents a good day on the Upper Mississippi River. South of St. Louis on the 730-mile journey to New Orleans and with no locks to slow down the tow, it's a different story.