Photo by Joel Despain

A mine shaft along Franklin Creek in Mineral King.

Today we are interested in mines for a different reason than wealth. Their presence in the parks is an important part of the history of the area, but their presence can also be dangerous for both people and the environment. All of the old mining sites in Sequoia are now abandoned and so come under the auspices of the Abandoned Mineral Lands Office of the National Park Services Geologic Resources Division, based in Denver, Colorado. This office has provided funding to assess the mines for hazards to both human health and safety and for their effects on the environment. Mine shafts and adits are often unstable, may contain toxic fumes or may suddenly end in deep drop-offs. They can be very dangerous places for the unprepared. The unusual chemistry of the rocks that are excavated at mines can often lead to acid mine drainage and heavy metal contamination. Both of these conditions can lead to poisonous environments near mines and contaminated water miles down stream from the mine site.

The good news in Sequoia and Kings Canyon is that the small, short-lived mines of this area do not seem to have produced these serious problems. The mines outside of Mineral King do not contain any shafts (vertical drop-offs) and do not seem to produce any acid mine drainage. In Mineral King, most sites also appear to be safe for people and the environment. However, at least one shaft in White Chief Valley might be dangerous. It is also possible that Franklin Creek in Mineral King may suffer from limited pollution problems associated with abandoned mines. The National Park Service will be reviewing and monitoring these problems in the future to insure that to the extent possible both visitors and the environment are protected in Sequoia and Kings Canyon.