Missouri Mines State Historic Site occupies Federal Mill No.

3 in Park Hills, Missouri, United States, which processed the lead and zinc ore that was mined in the immediate area for many decades.

The site's old power building features a geological and mining history museum and interpretive center focusing on the state's historic Old Lead Belt.

The mill was retired in 1972 as much of the ore in the area had been mined and major operations were moving west.

Much of the land was considered too damaged for return to a natural state and so became set aside for off-roading vehicles as St. Joe State Park, while the mill site was designated an interpretive center.