Okla. Stat. tit. 45 § 506
It shall be unlawful for the operator or superintendent, mine foreman or other person, to employ more than ten persons in any coal or other mine, or permit more than ten persons to be employed therein at any one time unless they are in communication with at least two available openings to the surface from each seam or stratum of coal or other mineral worked in such mine: Provided, that in any mine operated by shaft or slope and ventilated by a fan placed at the second opening, and said second opening is a slope or shaft, it may be used as an airway and for a traveling way into and from the mine, and if the said second opening is a shaft through which the employees travel into and from the mine, by reason of a stairway, or are regularly lowered into and hoisted from the mine by the use of machinery and such shaft is divided by suitable material into two compartments while developing or opening the mine up, to the ten men as hereinbefore, one of them may be used for an airway and the other for the purpose of ingress and egress into and from said mine; and further provided, that any fan shaft hereafter divided into compartments for the purpose of ventilation, and ingress and egress into and from the mines or any divided partition now in use that may hereafter be replaced, wholly or in part, shall be constructed of noncombustible material. And there shall be cut around the bottom of all hoisting shafts, or driven through the solid strata a traveling way not less than five (5) feet high and three (3) feet wide, to enable persons to pass from one side of the shaft to the other without passing over or under the cage or other apparatus, and there shall be cut around all other shafts a traveling way to save the necessity of passing under the shaft.
Okla. Stat. tit. 45, § 506