Wyo. Stat. § 30-2-407: Abandonment or closing down of mine; procedures to be followed.

(a) No owner or operator shall abandon or indefinitely close down any underground mine until the inspector performs a final inspection.

(b) Upon abandonment or closing down of an underground mine, the owner or operator shall effectively close or fence off all surface openings through which persons or animals could fall or enter.

(c) Upon abandonment or closing down of a strip or open-pit mine, mining or prospecting pit or excavation, appropriate action shall be taken where necessary to safeguard against injury to persons or animals.

(d) Within thirty (30) days after abandonment or closing down of any underground mine, the owner or operator shall file with the inspector a map showing all pertinent data as of the date of closing or abandonment in the form prescribed by the inspector. The map and all data shown thereon shall be confidential and not open for public inspection until (2) consecutive years have elapsed without resumption of mining activity, unless release has been authorized in writing by the owner or unless release is necessary for safety reasons shown by an adjoining operator or other person.