30 C.F.R. § 57.20021 Abandoned mine openings.
Title 30 - Mineral Resources
Upon abandonment of a mine, the owner or operator shall effectively close or fence off all surface openings down which persons could fall or through which persons could enter. Upon or near all such safeguards, trespass warnings and appropriate danger notices shall be posted.
Title 30: Mineral Resources
PART 57—SAFETY AND HEALTH STANDARDS—UNDERGROUND METAL AND NONMETAL MINES
Subpart S—Miscellaneous
§ 57.20021 Abandoned mine openings.
