Holston Mountain is a mountain ridge in Upper East Tennessee and southwest Virginia, in the United States. It is in the Blue Ridge Mountains part of the Appalachian Mountains. Holston Mountain is a very prominent ridge-type mountain in Tennessee's Ridge and Valley Region, about 28 miles (45 km) long, running from southwest to northeast, covering about 268 square miles (694 km²). Its highest summit is Holston High Point, on which a Federal Aviation Administration (FAA) aircraft navigational beacon is located, at an elevation of 4,280 feet (1,304.5 m) above mean sea level. The second highest point is Rye Patch Knob, at 4,260 feet (1,298.5 m) above mean sea level.