Interspersed among the forested high ridgelines of the southern Appalachians are about ninety mystifying clearings, known locally as balds. These patches predate European settlement, and the explanations for their presence range from lightning ﬁres to grazing by mammoths. Some of the patches are grassy balds; others, sometimes called slicks, are ﬁlled with laurels, rhododendrons, and other members of the heath family. (Gregory Bald, at nearly 5,000 feet in the Smokies, boasts twenty-one varieties of azalea.) Many of the balds are located in Great Smoky Mountains National Park; since cattle grazing is prohibited within its boundaries, managers now use weed-eaters and sickle-bar mowers to keep encroaching trees at bay.