Kan. Stat. § 18-123
The county of Douglas is bounded as follows: Commencing at the northwest corner of Johnson county, in the middle of the main channel of the Kansas river; thence up the main channel of said Kansas river, to the southwest corner of Leavenworth county; thence north on the west boundary line of Leavenworth county, to the north line of township twelve; thence west on said north line of township twelve, to the middle of the main channel of the Kansas river; thence up the main channel of said river, to the point where the line between the second and third tiers of sections in range seventeen crosses said river; thence south on the section lines, to the corner of sections fourteen, fifteen, twenty-two and twenty-three in township fifteen south, of range seventeen east; thence east on section lines, to the southwest corner of Johnson county; thence north along the west line of Johnson county, to the place of beginning.
K.S.A. 18-123