Mining continues to be a big industry in Idaho. Unfortunately a mine's life is not forever. Most mines close or become inactive for the usual reasons: The deposit is too small or peters out. Production costs exceed mineral value. Other mines can do it more profitably. The search for minerals runs up a dead end. And, of course, the old business axiom—prices drop when supply exceeds demand. Whatever the reasons, once interest in developing a mineral venture stops, the mine and the site are abandoned.
Thousands of mines and prospects have closed in the course of over a century of mining in the state. Most of these are abandonments that occurred before responsible site reclamation. The locations of many are remembered today; others are long forgotten. Nevertheless, the presence of these bygone operations may be hazardous to the environment and to humans, wildlife, and livestock. Problem sites contain mining byproducts and tailings that are sources of water and soil contamination. The former mines also have open workings and dilapidated structures—attractive historic nuisances perilous to the adventurous and unwary.
In 1996, the Idaho Geological Survey began recording the inactive mines in the northern part of the state. Researchers visit sites where they identify the hazards and map locations. They also videotape and photograph the locale for future reference. Individual histories have been prepared for some of these mines. The deaths in 1995 of two young men exploring an old mine awakened interest in the fateful importance of this work. The project has been funded by Region I of the U.S. Forest Service and the Idaho State Office of the U.S. Bureau of Land Management.