Wyo. Stat. § 30-2-408: Maps of mines to be made; contents; semiannual revision; maintenance and filing.

(a) The owner or operator of each mine shall make an accurate map or plan of the mine and mine workings on a scale not exceeding two hundred (200) feet to the inch or as otherwise approved by the inspector. The map or plan shall:

(i) Exhibit all openings or excavations, shafts, tunnels, slopes, planes, gangways, entries, cross headings, rooms and installations related to safety;

(ii) Show the direction of air currents in the mine;

(iii) Accurately delineate the boundary line between the mine and adjoining mines;

(iv) Be prepared with reference to and show the boundaries of the legal subdivision in which the mine is located;

(v) Be accurately brought up to date every six (6) months.

(b) The owner or operator shall:

(i) Maintain a copy of each map or plan for use at the mine by the inspector, his deputy or any miner employed at the mine;

(ii) File a copy of each map or plan with the inspector;

(iii) Maintain a copy of the current map or plan on bulletin boards near mine entrances and at all principal working stations.