Virginia Code Title 45.2. Mines, Minerals, and Energy § 45.2-728. Number of miners in openings

Until the two travel ways are made as required by § 45.2-726, no more than 20 miners shall work underground in the mine at one time. No additional development shall be permitted until the connection is made to the second opening. In a mine in which final pillar removal operations necessitate closing the second opening, no more than 20 miners shall be permitted to work in the mine.