In the North, wintering areas hold the key. Mature stands of low-elevation softwoods shelter deer from bitter winds and snow and are essential to their survival. In Michigan's Upper Peninsula, the north shore, which has relatively poor winter cover, supports an average of only five deer per square mile. But in the central and southern U.P., where large cedar swamps provide ideal cold-weather habitat, densities often exceed 25 per square mile. The same pattern is true in Maine: Within a 5- to 10-mile radius of a major "deer yard," the densities surpass those in areas that lack winter cover but are otherwise similar.