Below Echo Bridge the Charles keeps moving all winter, black water through Hemlock Gorge while snow stacks on the ledges above it. MOORESERVICES works the Upper Falls streets when a storm sets in overnight — the short steep drives off Chestnut and Elliot, the walkways that glaze first because the gorge holds the cold. Plowing there is a matter of angle and patience: back out clean, put the snow where it will not have to be moved twice. Salt goes down where the pitch asks for it, and the last look is always at the path to the door. Morning arrives late in that valley, and it is a fine thing to have the pavement already dark and open when it does.