Mo. Rev. Stat. § 245.540
The county commission of any county in which a levee district or a part of a district may be organized under the provisions of sections 245.285 to 245.545 may, for the purpose of constructing its levee, appropriate any of its unappropriated swamplands belonging to the county, and acquired under the provisions of an act of the Congress of the United States, entitled "An act to enable the state of Arkansas and other states to reclaim the swamp lands within their limits", approved September 28, 1850, and an act of the general assembly of the state of Missouri, entitled "An act donating certain swamp and overflowed lands to the counties in which they lie", approved March 3, 1851, and subsequent acts said lands to be received by the contractor at a price of not less than one dollar and twenty-five cents per acre.
§ 245.540, RSMo
RSMo 1939 § 12593