A clipper drops down out of Alberta and hits Wheeling sideways, dry snow skating across the open ground near the industrial drives off Wheeling Road until it piles against every loading dock on the block. Pro Plowing, Inc. is out in that at three in the morning — headlights, amber strobes, and the steady back-and-forth of a lot getting opened one pass at a time. Blades down the lanes, salt worked into the shaded strips where ice likes to sit, walkways cut wide enough for two people to pass each other. By the time the first shift rolls in, the pavement is dark and wet and the curbs are stacked high. Snow work in northern Illinois is measured in hours nobody sees, and that is exactly the point of it.