A cove soil is one which results from conditions that cause leaves to drift to the same spot season after season. The lee slopes of mountain tops all along the Appalachian Mountains develop cove soils, provided the windward slopes are covered with forest to produce the leaves. The annual increment of leaves keeps the soil always open, so that no water can leave the place where it falls until the entire soil mass has filled with water. The fertility of these soils is unbelievably high.