Coke is carbonized coal, a product produced by baking coal in a heated oven. By using a process that allows the impurities in the coal to be burned off, while not allowing the carbon content of the coal to burn, the coal is turned into coke. The impurities burned off were actually the volatile matter contained in the coal, such as tars, oils and gases. When burned, coke generated an intense amount of heat but produced very little smoke, qualities that made it an ideal fuel for use in producing iron and steal. During the 1880's, coke began to replace charcoal in the making of steel at foundries in the United States. By the end of World War I, eight-eight percent of the nation's iron and steel was produced by using a process utilizing coke. At a typical foundry of the era, coke and iron ore would be mixed together, and then burned in a furnace. As the coke burned, it would remove the oxygen from the iron ore, converting it to metal.

Practically all of the region's early coke plants used "beehive" coke ovens, so named because the interior of the oven was dome-shaped, similar to the shape of a beehive. Because the coal of the New River Coal Field made excellent coke, a large number of the area's coal operations built coke ovens near their coal plants. By 1906, more than 2,300 coke ovens were in operation in the mining camps of the New River Coal Field, of which 540 were located at mines along the C&O Loup Creek Branch. By the 1920's, the demand for coke slowed due to the expensive of the process, and the production of coke by the iron manufactures near their plants. Instead of using beehive coke ovens, a more efficient design was employed which allow gases and valuable chemicals to be recovered during the process of turning coal into coke. By 1942, Fayette County's production of coke had fallen to levels below what it produced in 1890.