Okla. Stat. tit. 45, § 45-506: Ventilation - Construction of air and hoisting shafts

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.