Our timing was great to see a freighter enter a lock from Lake Superior and then drop over 20feet to the rest of the Great Lake's water level.  In the third picture down the distant freighter was just entering and the close freighter was exiting.  We talked to a sailor on the near freighter and was told they were carrying 21,000 tons of Canadian grain.
We also took a ride through the Canadian locks and got to ride the water up & down, looks like everyone was excited to either watch a freighter at the campground......or me taking their picture.