Mo. Rev. Stat. § 451.230: How acknowledged or proved — to be recorded, where.

Such marriage contracts shall be acknowledged or proved before the same officer and certified in the same manner as deeds of conveyance for land are or shall be required by law to be acknowledged or proved and certified; and they shall be recorded, with the certificate of proof or acknowledgment, in the office of the recorder of each county where any estate is situated which is intended to be conveyed or affected thereby.