Somebody decorated the middle of the River for Halloween.  They would have gotten wet as the water level makes rock hopping impossible right now.  The third pumpkin says "Bowden Sunmaze" which is in Alberta when I Google it.  I don't know.  It's these little things that make me love the city in which I live.  Or the city in the next province over.  Not sure where the creative artist lives, but since there was nothing written in French I'd guess the Ontario side.