(225 ILCS 705/4.11) (from Ch. 96 1/2, par. 411)

Sec. 4.11. It is lawful for State Mine Inspectors to enter, examine, and inspect any and all coal mines and the machinery belonging thereto, at all reasonable times, by day or by night, but so as not to unreasonably obstruct, or hinder the working of such coal mines. The operator of every coal mine is required to furnish all necessary facilities for making the examination and inspection.

(Source: Laws 1953, p. 701.)