During the last Ice Age the Southern Appalachian spruce-fir forests and their animals must have been a richer version of the plant-animal community that exists in this zone today, for at the peak of the ice advance northern plants and animals probably could migrate along a continuous avenue of this boreal forest in the Appalachians. Bones from cave deposits at Natural Chimneys in Virginia’s Shenandoah Valley indicate that such northern animals as porcupines, snowshoe hares, pine martens, fishers, spruce grouse, and gray jays, as well as the now extinct longnosed peccary and giant beaver, roamed that area 10,000 to 15,000 years ago. The still existing species mentioned above now live farther north in the forests of New England and Canada. If such animals could live during the late Pleistocene at 450 meters (1,500 feet) in Virginia, many and perhaps all of them might well have lived at higher elevations in the Smokies. In the case of porcupines, archeological records from nearby regions in fact support this idea. After the retreat of the last ice sheet a warm, dry period set in and caused the development of grasslands as far east as Ohio. To what extent this change in climate may have affected the Smokies is not known. But it may have been responsible for the development of the beech gaps: as the spruce-fir forests were forced ever higher, beeches and yellow birches followed in their wake. The once continuous band of spruce-fir forest through the Southern Appalachians would then have been broken into patches as it migrated to higher elevations—and disappeared entirely on the lower mountains. Today such forest is restricted in the Southern Appalachians to the highest parts of eastern West Virginia, southwestern Virginia, western North Carolina, and areas in and just north of the Great Smokies. During the warmer, drier period following glaciation, boreal forest must have been even smaller in extent. Another consequence of warming was the northward migration of plants and animals into territory vacated by the ice sheet (north of the Ohio River and Long Island). The result today in northeastern United States is a broad patchwork of forest types, each type dominated by a few species, as in beech-maple or beech-birch-white pine forests. This stands in contrast to the diversity of the cove forests from which the migrants extended. Cove forests still harbor individuals of all these species. What happens next? Has the Pleistocene epoch really ended or are we merely between glaciers, awaiting the next invasion of ice? For the Smokies the question implies others: Will the forest zones move up or down the mountainsides? How will this affect animal life?