The Niagara Escarpment stretches across much of S. Ontario. It's a very long, tall, and rocky cliff with some neat lookout points. How much of a challenge was it for the Americans or the British to traverse around it? Did they ever use it to their advantage?
The main issue was that Niagara Falls prevented quick travel via boat.
It's pretty clear that the escarpment didn't prevent the Yanks from sacking York (Toronto) or the British from sacking Buffalo.
I crossed post this to /r/Buffalo as there might be a few resident historians who might better answer your specific question.