Mo. Rev. Stat. § 516.070
Whenever any real estate, the equitable title to which shall have emanated from the government more than ten years, shall thereafter, on any date, be in the lawful possession of any person, and which shall or might be claimed by another, and which shall not at such date have been in possession of the said person claiming or who might claim the same, or of anyone under whom he claims or might claim, for thirty consecutive years, and on which neither the said person claiming or who might claim the same nor those under whom he claims or might claim has paid any taxes for all that period of time, the said person claiming or who might claim such real estate shall, within one year from said date, bring his action to recover the same, and in default thereof he shall be forever barred, and his right and title shall, ipso facto, vest in such possessor; provided, however, that in all cases such action may be brought at any time within one year from the date at which this section takes effect and goes into force.
§ 516.070, RSMo