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 long, running from southwest to northeast, covering about 268 …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 long, running from southwest to northeast, covering about 268 square miles. Its highest summit is Holston High Point, on which a Federal Aviation Administration aircraft navigational beacon is located, at an elevation of 4,280 feet above mean sea level. The second and third highest points are Rye Patch Knob, at 4,260 feet above mean sea level and Rich Knob, at 4,240 above mean sea level respectively. The fourth highest point is Holston High Knob where an old dismantled Cherokee National Forest fire tower marks the elevation at 4,136 feet above mean sea level.