Beginning at the southwest corner of section eighteen, township sixty-four, range seventeen, west; thence east on the subdivisional lines to the middle of the main channel of the Chariton River; thence up Chariton River, in the middle of the main channel thereof, to the north boundary line of the state; thence west with said boundary line to the middle of range twenty-two; thence south with the subdivisional lines to the southwest corner of section thirty-four, township sixty-five, range twenty-two, west; thence east on the township line between townships sixty-four and sixty-five to the southeast corner of township sixty-five, range eighteen, west; thence south with the range line between ranges seventeen and eighteen to the place of beginning.