ABANDONED MINES IN THE UNITED STATES: CHALLENGES, OPPORTUNITIES, AND COLLABORATIONS

We estimate that there are more than one million abandoned mine features in the United States. Some are physical safety hazards, such as open shafts and adits; others generate environmental hazards, such as acidic waters that drain from mine tunnels. Some abandoned mine sites have mine waste features that could be reprocessed using modern technology to recover additional commodities, which in some places include critical minerals. Revenue derived from recovery of commodities could be used to help offset the costs of remediation, and reprocessing may produce materials that are less deleterious to the environment than what lies on the landscape now. Some State, Federal, and Tribal agencies have comprehensive inventories of abandoned mine features, and some agencies are just beginning these efforts. The U.S. Geological Survey’s mineral deposit database project (USMIN) is building comprehensive 21^st century geospatial databases that will be authoritative sources of information on where (1) abandoned mine features and (2) non-fuel mine waste features occur in the United States. We are collaborating with State, Federal, and Tribal agencies to advance this work. As of January 2024, we have received abandoned mine inventory data from the Bureau of Land Management, and contaminated sites inventory data from the National Park Service. State agencies from West Virginia, Kentucky, Nevada, New Mexico, and Colorado have also provided data, and USMIN is collaborating with California, Illinois, and Washington to obtain more data. The U.S. Geological Survey’s Earth Mapping Resources Initiative (Earth MRI) project has funded 13 state geological surveys to help build the non-fuel mine waste database, and this work is underway in Arizona, Illinois, Kentucky, Michigan, Montana, Nevada, New Mexico, North Carolina, Oklahoma, Virginia, and Washington. Collaborative efforts to build these national databases can establish the national need for abandoned mine remediation, and identify opportunities for reprocessing mine waste to recover critical minerals to help meet the national need.