Colorado Revised Statutes Title 34. Mineral Resources § 34-24-107. Danger signals--operator's duty

When operations are temporarily suspended in a mine, the operator shall see that danger signals are placed across the mine entrances, which signals shall be a warning for persons not to enter said mine. If the circulation of air through the mine is stopped, each entrance to said mine shall be closed off in such a manner as will ordinarily prevent persons from entering said mine, and a danger signal shall be displayed upon each entrance until such time as the ventilation is restored and the mine has been examined by a properly authorized representative. The mine foreman shall see that all danger signals used in said mine are in good condition.