Mo. Rev. Stat. § 46.056
Beginning on the western boundary of the state, at the southwest corner of section nineteen of township thirty-eight, range thirty-three, west; thence east with the subdivisional lines to the middle of the main channel of the Marais des Cygnes River; thence down said river, in the middle of the main channel thereof, to the middle of the main channel of the Osage River; thence down the Osage River, in the middle of the main channel thereof, to where the line between ranges twenty-eight and twenty-nine intersects the same; thence north with said range line between ranges twenty-eight and twenty-nine to the middle of the main channel of Grand River; thence up Grand River, in the middle of the main channel thereof, to the township line between townships forty-two and forty-three; thence west with the township line between townships forty-two and forty-three to the western boundary line of the state; thence south with the western boundary line of the state to the place of beginning.
§ 46.056, RSMo