Okla. Stat. tit. 66 § 161
Any railroad corporation chartered by or organized under the laws of the United States or any state or territory, whose constructed railroad shall reach or intersect the boundary line of this state at any point, may extend its railroad into this state from any such point or points to any place or places within the state, and may build branches from any point on such extension. 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 Corporation Commission, 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 such aid thereto as it would have had had it been authorized so to do by articles of association duly filed in accordance with the provisions of this article.
Okla. Stat. tit. 66, § 161