Mine waste is an understudied resource containing critical minerals needed for the economy and national security. In addition to exploring the subsurface for critical minerals, the U.S. Geological Survey and partners in Colorado are mapping aboveground resources to unlock the value in waste from active mines and legacy mining areas within the Colorado Mineral Belt.
The value of metal mine waste can rival that of new deposits. Leaving no pile of mine waste unmapped and untested is an important part of the larger national effort to strengthen America’s mineral and metal supply chains.
The potential is visible right here in the region. The Columbus Mine in La Plata County produced gold, silver, copper and lead until 1913. USGS aerial surveys suggested further investigation, and partners with the Colorado Geological Survey found concentrations of germanium, tellurium and tungsten. Today, the United States relies on imports for all three – germanium is used in night-vision goggles, tungsten in jet engines. China, the largest producer of germanium, already restricts its exports to the United States.
According to USGS studies, industries reliant on minerals contribute more than $4 trillion a year to the national economy. Yet as the United States grew increasingly dependent on imported minerals over the past 60 years, geologic mapping of our own resources slowed – falling behind countries like Canada, Australia and even some less-developed nations. At the same time, technological advancements created new demand for materials, while global supply chain disruptions and foreign export restrictions tightened supply further.
To respond to that challenge, President Donald Trump in 2017 signed Executive Order 13817 to secure reliable supplies of critical minerals. Since then, the USGS launched the Earth Mapping Resources Initiative. Working with state geological surveys, the USGS has flown aircraft equipped with cutting-edge geophysical instrumentation to map areas that might contain critical mineral deposits across more than 25% of the continental U.S., including high-priority areas like the Colorado Mineral Belt, which extends from Denver southwest to Durango.
Secretary of the Interior Doug Burgum has directed the USGS to complete a comprehensive national inventory of mine waste locations, mineral content, and recovery methods. Some inventorying has already begun in the Four Corners states. Using the vast repository of data captured by Earth MRI, along with decades of scientific research, the volume of critical minerals available from mine waste could contribute substantially to U.S. mineral independence.
A recent study by researchers at the Colorado School of Mines found that more efficient processing of waste streams from U.S. mines could provide much of the critical minerals the United States now imports. Simultaneously, environmental challenges presented by mine waste piles become opportunities for growth and cleanup. USGS research estimates there may be $2.5 billion worth of minerals and metals in mine waste across the Coeur d’Alene silver mining district in Idaho alone – a striking example of the potential to increase production while offsetting cleanup costs.
The USGS currently has agreements with 21 states to inventory and characterize mine waste – work that will help meet the needs of tech and defense manufacturers, grow the mineral economy, and help clean up the legacy of past mining operations.
With Earth MRI and state partners like Colorado, the USGS is mapping and remapping the nation's most promising areas to produce exploration data for the critical minerals we need – especially from the resource hiding in plain sight: mine waste.
Dr. Ned Mamula of Reston, Virginia, is director of the U.S. Geological Survey in the Department of the Interior. He holds a doctorate in geology from Texas A&M University.
