Yes Rachel, there is a Holston River. It is a major river system of Southwest virginia and East Tennessee. The three major forks of the Holston river (its North, Middle and South Forks) rise in southwest Virginia and have their confluence near Kingsport, Tennessee. From there the river flows roughly southwest, just north of Bays Mountain, until it reaches its confluence with the French Broad river just east of downtown Knoxville, Tennessee. This confluence is considered to be the headwaters of the Tennessee river.
The Holston River valley is greatly developed for electrial power generation, both with hydroelectric dams and coal-fired steam plants. In its upper reaches some of these plants are controlled by private interests; in the downstream portion they are owned by the United States Goverment's Tennessee Valley Authority.
The river was named after Stephen Holston, who built a cabin on the upper reaches of the river in 1746. Holston Mountain was named after the Holston River.
You didn't know you were going to get a history lesson, did you? LOL