THE coal seams in the State mine area occur in localities scattered over a stretch of country approximately 41 miles long by 3 miles broad, as will be seen from an inspection of Plate I. at the end of this paper. Plate II shows existing transmission lines and those proposed in the near future. These natural conditions made it necessary for any central electrical plant designed to supply power for coal-mining operations to be of a fairly high potential: for economical distribution. The problem of designing such a -central plant was started towards the latter part of 1910, and a three-phase 5000 volt generation and distribution voltage was decided on. This voltage is quite satisfactory up to 6 or 7 miles transmission, and presents no out-of-the-way difficulties of operation. Specifications were prepared on the lines laid out, and tenders closed in December, 1910. The plant was completed in June, 1912.