The Big Sandy River and its two main branches, the Tug Fork and Levisa Fork, form the southwestern border of West Virginia with Kentucky. The two forks begin about 20 miles apart and flow north to join at Louisa, Kentucky. The main Big Sandy River then flows to the Ohio River. The Tug Fork and then the Big Sandy River form the entire border between West Virginia and Kentucky.

The area is known for its rugged forests and coal mining. It also was the location of the Hatfield-McCoy feud in the late 1800s.

For many years, the river was the main way people in that region connected with the outside world. From the 1830s to the 1930s, steamboats carried people, mail, and goods. Loggers also built temporary dams to create floods to float huge rafts of timber downriver.

Railroads arrived in the late 1880s, making coal mining the main business. Trains and then cars eventually replaced the old riverboats, but part of the Big Sandy River is still used for commercial navigation today.