Six Mile Creek comes down its valley from Brooktondale through hemlock shade and shale ledges, and the whole southeast side of Ithaca is shaped by that run of water. Six Mile Exterior Cleaning Solutions works the yards along it — mowing, trimming, edging and clearing away what a season leaves behind on a property. Grass in the valley stays green late, fed by the damp, and a lawn there can carry a crisp cut line well into October. There is a plain pleasure in the finish: clippings blown off the walk, the border sharp, the whole yard reading as one clean shape from the road. Then the leaves come down out of the gorge trees, and it all starts over again.