Abstract The mining of zinc in Tennessee dates back to 1854 although the presence of zinc minerals had been reported as early as 1844 by Gerard Troost, the first State Geologist. When the Mossy Creek open pit mine, in what is now Jefferson City, Jefferson County, was opened, it became the first mine in what is now known as the Mascot-Jefferson City Zinc District. In these early years, only the oxidized ore was removed, and mining stopped when the sulfide ore zone was reached because a method to treat “hard ore”, as it was called, had not yet been developed. Mining continued at the Mossy Creek operation until 1858, then ceased through the Civil War years until 1867, at which time the property was taken over by the East Tennessee Zinc Company. This company built a smelter to manufacture zinc oxide, but after only a few months of operation, the company became involved in litigation and mining ceased. In 1882, the Mossy Creek property was sold to the Eades, Mixter and Heald Zinc Company which operated intermittently until 1894, becoming the first substantial zinc mining company in Tennessee as well as the first to produce significant amounts of sulfide ore. This latter was made possible by the construction of a zinc smelter at Clinton, Tennessee, some 45 rail-miles to the west. The Mossy Creek mine was operated or prospected only sporadically thereafter, and was closed by its final owner, the American Zinc Company, in 1919. In the meantime, the discovery of lead and zinc ore in the Powell River area of Claiborne and Union Counties, some 30 miles northwest of Jefferson City, caught the attention of the mine operators.