77.1200—Mine map.
The operator shall maintain an accurate and up-to-date map of the mine, on a scale of not less than 100 nor more than 500 feet to the inch, at or near the mine, in an area chosen by the mine operator, with a duplicate copy on file at a separate and distinct location, to minimize the danger of destruction by fire or other hazard. The map shall show:
(c)
Contour lines passing through whole number elevations of the coalbed being mined. The spacing of such lines shall not exceed 25-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.
(d)
The general elevation of the coalbed or coalbeds being mined, and the general elevation of the surface;
(f)
The location and elevation of any body of water dammed 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;
(g)
All prospect drill holes that penetrate the coalbed or coalbeds being mined on the mine property;
(h)
All auger and strip mined areas of the coalbed or coalbeds being mined on the mine property together with the line of maximum depth of holes drilled during auger mining operations.
(j)
The location of railroad tracks and public highways leading to the mine, and mine buildings of a permanent nature with identifying names shown;
(l)
The location and description of at least two permanent base line points, and the location and description of at least two permanent elevation bench marks used in connection with establishing or referencing mine elevation surveys; and,