The county of Dawson is bounded as follows: Commencing at the southwest corner of township nine, north, of range twenty-five, west; thence east to the center of the south channel of the Platte River; thence down said channel to a point where the dividing line between ranges eighteen and nineteen intersects the same; thence north along said dividing line to the northeast corner of township twelve, north, of range nineteen, west; thence west to the northwest corner of township twelve, north, of range twenty-five, west; thence south to the place of beginning.