Discover the hidden Empire Mine via the scenic Samelius Trail in South Dakota's Black Hills.

From Europe to North America, an energy revolution is breathing new life into empty, long-forgotten coal mine shafts—by repurposing them into places to store renewable energy. Using "gravity batteries ...

New Jersey lawmakers are moving to plug the state’s most dangerous abandoned mines, the same hidden hazards blamed for sinkholes that swallowed sections of I-80 earlier this year, under a bill that ...