Vent raise, Colorado School of Mines Experimental Mine
The Colorado School of Mines Experimental Mine is located in Idaho Springs, Clear Creek County, Colorado. Originally known as the Edgar Mine, it produced silver and gold, and some lead and copper in the 1870s. The Big Five Mining Company leased the Mine to the School of Mines for training in 1921. The School eventually acquired the Mine and additional workings to develop the Experimental Mine as an underground classroom for engineering education and as a research facility. The Edgar's workings include the Miami Tunnel, the Edgar shaft following the old Edgar vein, and the Big Five Tunnel.