Additional information required to be shown on mine maps under Sec. 75.1200 shall include the following:
(a) Name and address of the mine;
(b) The scale and orientation of the map;
(c) The property or boundary lines of the mine;
(d) All drill holes that penetrate the coalbed being mined;
(e) All shaft, slope, drift, and tunnel openings and auger and strip mined areas of the coalbed being mined;
(f) The location of all surface mine ventilation fans; the location may be designated on the mine map by symbols;
(g) The location of railroad tracks and public highways leading to the mine, and mine buildings of a permanent nature with identifying names shown;
(h) The location and description of at least two permanent base line points coordinated with the underground and surface mine traverses, and the location and description of at least two permanent elevation bench marks used in connection with establishing or referencing mine elevation surveys;
(i) The location of any body of water dammed in the mine or held back in any portion of the mine; provided, however, such bodies of water may be shown on overlays or tracings attached to the mine maps used to show contour lines as provided under paragraph (m) of this section;
(j) The elevations of tops and bottoms of shafts and slopes, and the floor at the entrance to drift and tunnel openings;
(k) The elevation of the floor at intervals of not more than 200 feet in:
(1) At least one entry of each working section, and main and cross entries;
(2) The last line of open crosscuts of each working section, and main and cross entries before such sections and main and cross entries are abandoned;
(3) Rooms advancing toward or adjacent to property or boundary lines or adjacent mines;
(l) The elevation of any body of water dammed in the mine or held back in any portion of the mine; and,
(m) Contour lines passing through whole number elevations of the coalbed being mined. The spacing of such lines shall not exceed 10-foot elevation levels, except that a broader spacing of contour lines may be approved by the District Manager for steeply-pitching coalbeds. Contour lines may be placed on overlays or tracings attached to mine maps.
(n) The locations of refuge alternatives. [35 FR 17890, Nov. 20, 1970, as amended at 73 FR 80697, Dec. 31, 2008]