Up on the Mendham hills the snow starts earlier and stays later than it does down in the valleys, and a storm that gives the lowlands an inch will give these ridges three. SDC Contracting Inc. answers that at two or three in the morning — plowing the long township driveways, the ones with a bend and a grade and a gatepost you have to know by heart in the dark. Ice gets salted, walkways get opened, and the mailbox turnaround gets a pass so the day can happen normally. There is a good hour near the end of a route when the plowing is done and the sky over the bare oaks goes from black to slate. Everything cleared, everyone else still asleep.