Once the big chill sets in, crappies begin sliding offshore and into deeper water in the North. Basically, they retreat to the mouths of creek arms or large bays, but their winter deep-water hunting grounds vary with the type of lake or reservoir. In bodies of water whose main structure is a river channel with secondary channels off it, they'll be right on the drop or down in the channel. Ledges with steep drops are favorite hangouts in other waters, as are deep holes in bays, along with deep flat areas. A favored winter depth in lakes I've fished around the country is 30 feet. Fish could be 10 feet or so to either side of this magic mark. You'll often discover cold-weather crappies hunting minnows where the preferred depth pushes toward shore adjacent to deep-water points, humps or bars rather than on the structure.