All rolling stock of any railroad corporation organized under the provisions of this article, used and employed in connection with its railroad, and all fuel necessary to the operation of the same, are declared and shall be held to be fixtures; and all such property, and all additional rights-of-way, depot grounds, and other real property, acquired subsequently to the execution of any trust deed or mortgage which shall have been described or provided for therein, shall be subject to the lien thereof to the same extent as the property therein described, which the corporation owned at the time of its execution.
Okla. Stat. tit. 66, § 14