Although the Cherokee transferred possession of what is now Campbell County to the United States in 1805, the northern Elk Valley remained sparsely populated for most of the 19th century.
 A road connecting Campbell County with Kentucky passed through the area, and may have been used by a detachment of the Confederate Army of East Tennessee to invade Kentucky in 1862 during the U.S. Civil War.
 A village known as "Smithburgh" eventually developed in the vicinity of this road, but by 1878, Smithburgh consisted of little more than a post office and a half-dozen houses.

In the early 1880s, a high quality type of coal was discovered on Jellico Mountain.
 Jellico coal, as it came to be known, burned relatively slowly and had a low ash content.
 In 1883, Smithburgh changed its name to Jellico in part to capitalize on the new demand for this coal.
The discovery of coal coincided with the arrival of the railroad, making large-scale mining in the area economically feasible, and mining operations sprang up throughout the Elk Valley.

In the late 19th century and early 20th century, most coal mining operations focused on underground mining.
 With the success of Jellico coal, Campbell County became the largest coal producer of any county in Tennessee, producing over one million tons (appx.
900,000 metric tons) per year between 1912 and 1924.
 By the 1940s and 1950s, however, surface mining had become the mining companies' preferred coal extraction method.
 During this period, the Saxton Coal Company operated a large surface mine at what is now Indian Mountain State Park.
 In 1960, after the mine's coal resources had been exhausted and the mine abandoned, the City of Jellico obtained ownership of the mine and with the help of several state and federal agencies, began restoring the denuded, unattractive land.
 Indian Mountain State Park opened in 1971.
Although the Cherokee transferred possession of what is now Campbell County to the United States in 1805, the northern Elk Valley remained sparsely populated for most of the 19th century.  A road connecting Campbell County with Kentucky passed through the area, and may have been used by a detachment of the Confederate Army of East Tennessee to invade Kentucky in 1862 during the U.S. Civil War.  A village known as "Smithburgh" eventually developed in the vicinity of this road, but by 1878, Smithburgh consisted of little more than a post office and a half-dozen houses.
In the early 1880s, a high quality type of coal was discovered on Jellico Mountain.  Jellico coal, as it came to be known, burned relatively slowly and had a low ash content.  In 1883, Smithburgh changed its name to Jellico in part to capitalize on the new demand for this coal. The discovery of coal coincided with the arrival of the railroad, making large-scale mining in the area economically feasible, and mining operations sprang up throughout the Elk Valley.
In the late 19th century and early 20th century, most coal mining operations focused on underground mining.  With the success of Jellico coal, Campbell County became the largest coal producer of any county in Tennessee, producing over one million tons (appx. 900,000 metric tons) per year between 1912 and 1924.  By the 1940s and 1950s, however, surface mining had become the mining companies' preferred coal extraction method.  During this period, the Saxton Coal Company operated a large surface mine at what is now Indian Mountain State Park.  In 1960, after the mine's coal resources had been exhausted and the mine abandoned, the City of Jellico obtained ownership of the mine and with the help of several state and federal agencies, began restoring the denuded, unattractive land.  Indian Mountain State Park opened in 1971.
Indian Mountain State Park