As you're aware, we are big fans of our state park system. Missouri has many lovely sites to enjoy and those with historical significance are of particular interest to us. Several weeks ago we played hooky one day to visit a few places we'd not previously visited. The first stop of our all-day excursion was Missouri Mines Historic Site in Park Hills, MO.
The original plant was built by Federal Lead Company in 1906 where lead and zinc ore were mined. The photo below shows how the complex looked in its day.
In the early 1920s, the plant was sold to St. Joseph Lead Company where production continued until it closed in 1972. A few years later, the land was donated to the state. Today, the old original buildings remain onsite for visitors to observe (due to their condition, they cannot be entered).
Mining machinery is on exhibit in a mining hall.
A complete mineral museum highlights multiple examples (as shown below). There is also a very good historical movie which provides an interesting and informative overview of the actual mine.
Missouri Mines Historic Site is open yearlong with limited off-season hours. Throughout the spring and summer, they're open daily (hours vary). There is a nominal fee to enter the museum.
We would recommend this site to others. Maybe you can stop to see it if you're ever in the area.