Current State of Underground Mining Mining Method Classification and Description Planning an Underground Operation Cost Estimating Shaft Sinking Subsurface Mine Development Underground Openings and Other Infrastructure Accessing the Ore Body Vein Mining Sublevel Caving Block Caving Cut-and-Fill Mining Mine Backfill Room-and-Pillar Seam Mining Longwall Mining Biohydrometallurgy Underground Rock Mechanics and Ground Control Mechanical Rock Breaking Underground Drilling Underground Blasting Movement of Ore and Waste to the Surface Managing Water in Underground Mines Mine Ventilation Subsurface Surveying Underground Electrical Power and Lighting Mechanization, Automation, and Digital Transformation Communication, Monitoring, and Control Mine Maintenance and Repair Emergency Response Mine Safety, Occupational Health, and Worker Well-Being Environmental, Social, and Governance Issues