Oh Canadians, forever nice. To walk to Canada from the U.S. is free of charge. The good ol’ U.S. of A will charge you 50 cents for your return, though. Canadian customs always has at least two agents on duty. Niagara Falls State Park has a bridge called Rainbow Bridge that you can park by and walk across to Canada.
It’s pretty handy, because you can view a lot of the park while walking across and site see some. You have to have a passport to get into Canada and the U.S., which is different than it was a few years ago. It isn’t allowed to walk halfway across the bridge and then return. You have to go all the way across, go through customs, turn around, and then get back into the U.S. Niagara Falls is visible from Rainbow Bridge, which allows for a nice view if you are driving across, because you have something to look at while you wait in line.