C.R.S. § 30-5-170: Washington.

(1) The county of Washington is hereby established, with the same legal capacity and functions as other counties of this state, and the boundaries are as follows:

Beginning at the southeast corner of Weld county, and running thence west along the south boundary of Weld county to a point at the west line of range fifty-four west of the sixth principal meridian; thence north along the west line of said range fifty-four to a point on said range line at the north line of township five, north of range fifty-four west; thence east along said north line of township five north, and continuing on said course direct to a point on the east boundary line of the state, and of said Weld county; thence south along the east boundary line of the state and Weld county to the place of beginning.

(2) There is hereby stricken from the county of Adams, formerly a part of the county of Arapahoe, and annexed to the county of Washington, all that territory now a part of Adams county, formerly a part of Arapahoe county, described as follows:

Beginning at the intersection of the east boundary line of range forty-nine west and the north boundary line of Adams county; thence west along the north boundary line of said Adams county to the east boundary line of range fifty-seven west; thence south along said line to the south boundary line of said Adams county; thence east along the southern boundary of said Adams county to the east boundary line of range forty-nine west; thence north along said line to the place of beginning.