Snow falls differently in the Bird Hills ravines — it comes down through bare sugar maples and lands without a sound, and by midnight the road up is a white ribbon running between black trunks. Canopy Landscapes takes the plows through that hour, opening drives on the wooded west side and shoveling the steps and switchback walks that drop down to them. Salt goes wherever shade keeps ice all winter, which in these hollows is nearly everywhere. Winter is the entire trade here and it gets the whole of the attention: a route run in order, a driveway open before the alarm sounds. Morning comes and the hill is simply passable. That is the work.