The Saginaw River runs cold and steady past the Veterans Memorial Bridge all winter, and the wind that follows it downtown will pack a parking lot solid overnight. Tri-Valley Construction, LLC. handles the snow side of that season — plowing lots and drives, opening approaches, clearing walks, and salting where ice wants to set. Big pavement takes a plan: where the piles go, which lane opens first, how to keep an entrance from rutting by the second storm. Getting it finished before the day starts is the entire measure of the job. By the time traffic moves, the lot looks like it never snowed.