30 C.F.R. § 75.1711-3 Openings of active mines.
Title 30 - Mineral Resources
The openings of all mines not declared by the operator, to be inactive, permanently closed, or abandoned for less than 90 days shall be adequately fenced or posted with conspicuous signs prohibiting the entrance of unauthorized persons.
Title 30: Mineral Resources
PART 75—MANDATORY SAFETY STANDARDS—UNDERGROUND COAL MINES
Subpart R—Miscellaneous
§ 75.1711-3 Openings of active mines.
