Whoa - where am I??? Not in Great Falls, Montana. This is the Great Falls of the Potomac River in Maryland, which I visited when I was back East for my son's wedding.
The locks next to the river are part of the Chesapeake and Ohio Canal, which ran 185 miles between Cumberland, MD and Washington, DC. There are 74 locks along the way.
The canal operated between 1831 and 1924. Today, tour boats take you through a few of the locks.
The boats are pulled by mules, just like in the olden days.
When the boat gets into the final lock, the mules are given a rest and the historically-clad humans take over.
First the water is let out, then the lock is opened.
And out they come!
At this point, it gets really interesting. The boat needs to be turned around, which is done by women with poles.
Then the passengers are let off.
You can also go out a walkway to view the falls. Believe it or not, people kayak down it!