Mo. Rev. Stat. § 59.163

59.163. Instruments where recorded or filed in counties of first class having two recording offices. — In any county of the first class in which the recorder of deeds is required by law to keep offices both at the county seat and at another place within the county, all deeds, deeds of trust, mortgages, and other instruments affecting real property situated in that range in the county where the office outside of the county seat is located shall be recorded in such office and not at the county seat; and the proper place to file, or to file for record if goods are or are to become fixtures, is as follows:

(1) When the collateral is goods which at the time the security interest attaches are or are to become fixtures, and the land to which the fixtures are or are to be attached is located in that range where the office outside the county seat is located, then in such office outside the county seat, and any such filing shall be for record;

(2) In all other cases where the proper place, or one of the proper places, to file or to file for record is in the office of the recorder of deeds of such county, then only in such office at the county seat and not in such office outside the county seat;

(3) All financing statements or other instruments or statements incidental thereto, such as continuation statements, termination statements, statements of assignment, in order to perfect, continue, terminate, assign, release, or affect a security interest in accordance with article 9, chapter 400 , the uniform commercial code, shall have priority over liens filed under this section for the time period after June 30, 2001, and before August 28, 2003.

(L. 1957 p. 347 § 1, A.L. 1965 pp. 114, 170, A.L. 1969 H.B. 677, A.L. 2003 H.B. 221 merged with S.B. 346)