Okla. Stat. tit. 66 § 166
Every railroad corporation organized under the laws of any other state or territory or the United States, that within three (3) years before the taking effect of the Constitution of this state, shall have complied with the laws of the Territory of Oklahoma or Indian Territory, to authorize such corporation to transact business in the Territory of Oklahoma or Indian Territory or either or both of them, and that shall file with the Secretary of State of this state a resolution of its board of directors duly certified by its president and attested by its secretary under the seal of such corporation accepting the provisions of the Constitution of this state and agreeing that the Constitution and laws of this state applying to domestic corporations shall apply to such corporation in all respects, is hereby declared to be a domestic corporation under the Constitution and laws of this state.
Okla. Stat. tit. 66, § 166