Wherever man goes, garbage follows. And in order to manage it, garbage receptacles are necessary. Banff has hundreds of them, and it's hard to image what the landscape would look like without them. It's a sign of man's presence and almost brings a feeling of security that infrastructure is present to wisk away any garbage that you might be caught holding on to.
But, the landscape did exist without them. So when you see one, ponder how unnatural it really is.