30 C.F.R. § 57.11058 Check-in, check-out system.
Title 30 - Mineral Resources
Each operator of an underground mine shall establish a check-in and check-out system which shall provide an accurate record of persons in the mine. These records shall be kept on the surface in a place chosen to minimize the danger of destruction by fire or other hazards. Every person underground shall carry a positive means of being identified.
Title 30: Mineral Resources
PART 57—SAFETY AND HEALTH STANDARDS—UNDERGROUND METAL AND NONMETAL MINES
Subpart J—Travelways and Escapeways
Escapeways—Underground Only
§ 57.11058 Check-in, check-out system.

