Ohio Rev. Code § 1567.07: Entry beyond danger signal.

In gaseous and nongaseous mines, no person other than a mine foreman or fire boss, or owner, lessee, agent, or operator of the mine, or a representative of either accompanied by a mine foreman or fire boss, shall remove or go beyond any caution board or danger signal placed at the entrance to any working place or old workings in a mine, unless permitted to do so by either a mine foreman or a fire boss after such mine foreman or fire boss has acquainted himself with the danger lying beyond such caution board or danger signal.