Mo. Rev. Stat. § 470.170: Lands claimed within five years, by whom.

Within five years after judgment has been rendered, any person, other than those who were served with the scire facias, or appeared to the proceedings, their heirs or assigns, may appear and claim lands vested in the state and may file his petition in the circuit court of the county in which such estate is situate, setting forth the nature of his claim, and praying that the said estate may be relinquished to him.