This rendering of digital elevation data available from New York state shows how the Mohawk Valley narrows dramatically at Little Falls. The modern Erie Canal bypasses the rapids, just like the original canal did in 1825, but rejoins the river below Lock No. 17. In 1825, five locks were required to lift the canal around the falls, but Lock No. 17, with a lift of 40.5 feet, eventually replaced all of them. (Digital elevation data from NYS GIS, rendering by Steve Boerner)