27-366. Maps of underground workings
When ordered by the inspector, the operator of every underground mine shall make and maintain a reasonably accurate map of the workings of the mine. At least once every six months or oftener if necessary, the operator shall make alterations or additions to the map showing excavations made since those last shown on the map. All parts of the mine which were worked or abandoned shall be clearly indicated and all underground workings shall be surveyed and mapped before they become inaccessible. The maps shall at all times be open to inspection by the inspector.