At the dam the Fox keeps moving all winter, a dark seam of open water in the middle of a white county. Grounds Group works the frozen part — plowing driveways and lots across McHenry, clearing walks, and spreading salt where a thaw-and-freeze cycle has turned a surface to glass. Storms come in fast off the northwest, so the routes are built to be run more than once when the snow keeps up. It is plain work with a plain reward: a property somebody can get into and out of before the sun is up. Plow routes take in McHenry, Johnsburg, Lakemoor and Holiday Hills.