Sebewaing sits where its crooked little river lets go into Saginaw Bay, and the wind that comes off that ice in January has nothing at all to slow it down. Tri County Lawn & Snow works in that wind — plowing driveways and lots, clearing walks, salting the spots that glaze over between the harbor and the beet fields. Summer turns the same town soft and green, and the round becomes mowing, trimming and edging, week in and week out. Both jobs come down to the same thing: a property somebody can walk across without thinking twice about it. In the Thumb, where the weather is honest about itself, that counts for a great deal.