A clipper drops down out of the northwest with nothing in its way, and by the time it reaches the Mississippi the snow is moving sideways across South Moline. Bettendorf Snow Solutions works those nights, plowing driveways, opening lots, clearing walks and laying salt while most of the valley is asleep. Near four in the morning the blade throws its last windrow off a drive and the pavement behind it goes simply dark and open, which is the point of the entire exercise. Winter here can show up between one evening and the next, and the trucks roll for it either way. By the time headlights start crossing the river bridges, the way out has already been made.