Mingo County's thick, high-quality coals above and below the surface traditionally ranked it as one of West Virginia's top coal-producing counties. Numerous coal camps in Mingo County housed miners and their families. Williamson's Coal House, a 1933 tribute to coal's regional importance, is on the National Register of Historic Places. The railroad's arrival in 1892 provided the reliable transportation needed for the coal and timber industries to boom. The Norfolk and Western, now Norfolk Southern Railroad, was the state's southern link between the Ohio River and the East Coast. Williamson's rail yard, the largest between Portsmouth, Ohio, and Bluefield, West Virginia, is still a key transportation link for coal, lumber, and other products brought in and out of the area.