Large-scale underground hardrock mining and open-pit extraction did not completely stop in Butte, Montana; rather, operations shifted dramatically due to changing economic conditions, shifting corporate ownership, and the sheer scale of the Berkeley Pit super-site. While historic underground tunnels closed as low-cost open-pit extraction took over in the latter half of the twentieth century, modern technological advancements allowed companies like Montana Resources to continue active extraction of copper and molybdenum from the Continental Pit, maintaining the city's proud mining heritage.