Okla. Stat. tit. 66 § 9
Any railroad corporation may, under the provisions of this article, extend its road from any point named in its charter or articles of organization, or may build branch roads either from any point on its line of road or from any point on the line of any other road connecting or to be connected with its road, the use of which other roads between such points and the connection with its own road such corporation shall have secured by lease or agreement for a term of not less than ten (10) years from its date. Before making such extension or building any such branch road, such corporation shall, by resolution of its directors, to be entered in the record of its proceedings, designate the route of such proposed extension or branch in the manner provided in Section 1376, and file a copy of such record, certified by the president and secretary, in the office of the Secretary of State, and cause the same to be recorded as provided in said Section 1376. Thereupon such corporation shall have all the rights and privileges to make such extension or build such branch and receive aid thereto which it would have had if it had been authorized in its charter or articles of organization. But this section shall not be construed to authorize any railroad corporations to consolidate with each other.
Okla. Stat. tit. 66, § 9