K.S.A. 18-1,101

The county of Washington is bounded as follows: Commencing at a point where the east line of range five east intersects the base line of the state of Kansas; thence south on said range line, to the first standard parallel; thence west with said parallel, to the sixth principal meridian; thence north with said meridian, to the base line of the state of Kansas; thence east with the said base line, to the place of beginning.