In about 1905 a drainage tunnel company built a single circuit 6,600-volt transmission line to several substations that fed underground compressors and mining equipment over a 1000-ft below ground along with mines all over the district. About 1910 the line was rebuilt at 13,200-volts double circuit and many miles of extensions were made. All of the line construction shown here is ancient with modifications made across a 100 year time frame.