Snow reaches the high streets north of downtown before it ever reaches the river, and the hills above Route 97 stay white for days after the valley has gone back to gray. LEO LAWN CARE Corp runs both sides of that calendar: plowing driveways, opening walkways and salting the steep aprons in winter, then mowing, trimming and edging once the frost lets go of the ground. Winter work in Haverhill is mostly a question of grade — a driveway that climbs has to be scraped down to blacktop, not merely skimmed. By July those same properties want stripes and sharp borders instead. Two very different trucks, one list of houses, and the same thing owed to every one of them.