Mo. Rev. Stat. § 429.530: Who shall be parties to suit.

Any person or corporation owning or operating the railroad to which said liens may apply shall, in each instance, be made a party defendant in all suits for enforcing said liens; but it shall not be necessary to make the party with whom the contract was made for doing the work and labor, or for furnishing of material, a party defendant in such suit; but such party or parties may, at the option of the plaintiff, be made parties defendant, in which case process may be awarded and served as other writs of summons in any county in this state.