During the first fifteen years of operation, although the mine was doing relatively well, the work was slow and inefficient, especially in the use of oxen to transport the lead ore and mules to haul supplies. To speed up operations, in 1880 the company decided to build a narrow-gauge railroad line to its smelting mill. Then in 1887, the company built another rail line to the Mississippi River south of St. Louis (at the town of Herculaneum) in order to get the ore to customers even faster. Before that, it had to pay to use another rail line to St. Louis.
The Bonne Terre mine continued to operate until 1962 when the lead ore ran out. It was very productive over its lifespan, producing 35 million tons of lead valued at around $300 million.