I've landed on a number of the national park lakes in Southern Alberta a couple of hundred times and nobody complained! Could have had something to do with the load of water I was scooping to put out their fires, though. Absolutely stunning landing on the blue-green lakes like Minnewanka near Banff! Didn't see a floatplane the whole time I was out there, or boats for that matter. I might have seen a few canoes!
If you want floatplanes, head to Northern Ontario. Red Lake, Kenora, Sioux Lookout, Pickle Lake, etc... That's floatplane central in that area. Beautiful in the summer, too!