In the great Displays at the museum I learned a few things (John did a great explanation of how the Locks actually work) & these stood out:
If all the water in the 5 Great Lakes was spread across the U.S., the entire surface of the country would be under nine & a half feet of water. That’s a LOT of water.
The size of the longest freighters going through the Locks are 1,000 feet long, just 250 feet shorter than the Empire State Building. Here’s a photo of Part of one Lock:
0017 part of a Lock
The Locks are Very protected because of their economic importance. In fact, a guard went through my purse to check for guns before we could enter the museum.
John & Anne Wiley 
Wow, I wouldn’t have guessed that it would be enough water to cover the country in 9′ of water! It was funny to hear you mention the locks in Seattle because that was my first thought when I read the title. They are the only locks I have been to and it was on my first visit to see Christine and her family in Seattle. Enjoy the rest of your trip and thank you for taking time to update us.
Comment by Jasen — 2010/07/29 @ 14:39