Beginning in the middle of the main channel of the Missouri River, opposite the mouth of Moniteau Creek; thence up said creek to the line between townships forty-eight and forty-nine; thence in a direct line to the northeast corner of township fifty-one of range fourteen, west; thence in a direct line to a point one and a half miles west of the northeast corner of township fifty-two of range seventeen, west; thence in a direct line to a point in the middle of the main channel of the Missouri River, where the line between sections seventeen and twenty, township fifty-one, range seventeen, west, intersects the same, and thence down the same, in the middle of the main channel thereof, varying, however, if necessary, so as to include the first island below the city of Boonville, to the place of beginning.