(1) For purposes of descriptions of boundaries, any highway designation is measured from the center line of the highway, as determined by Washington department of transportation maps.

(2) Brassica seed production district 1 includes areas of five counties as follows:

(a) In Whatcom County, the area is bounded as follows: From two miles west of the Interstate 5 intersection with the Canadian border, a southward line extends parallel to, and two miles west of, Interstate 5 to its intersection with State Highway 542. The line then extends generally northeastward along State Highway 542 to the city limits of Kendall. At Kendall, the line continues due north to the Canadian border. The line then extends westward along the Canadian border to its point of origin.

(b) All of mainland Skagit County is included. On Fidalgo Island, the area on its eastern side bounded by a line three miles west of and parallel to the Swinomish Channel, extending from Padilla Bay to Similk Bay, is included. All of Samish Island is included. The remaining portion of Fidalgo Island and all other islands in Skagit County are excluded from Brassica seed production district 1.

(c) In Snohomish County, the area is bounded as follows: From Puget Sound east along State Highway 531 (also known as Lakewood Rd.), the line extends through Interstate 5 Exit #206 (the Smokey Point exit) to the intersection of State Highway 531 and State Highway 9 in Arlington. From there the line extends generally northward along State Highway 9 to the county line, and then west along the county line to Puget Sound.

(d) In Island County, all of Camano Island and the portion of Whidbey Island north of an east-west line extending through Greenbank.

(e) In Clallam County, the area is bounded as follows: From the westernmost city limit of Port Angeles, a line extends due south to a location five miles south of State Highway 101. From there, the boundary continues east along a line parallel to, and five miles south of, State Highway 101 to the Clallam/Jefferson County line. The boundary turns north along the Clallam/Jefferson County line until it reaches the Straits of Juan de Fuca and then continues along the Straits to its point of origin.

(3) Brassica seed production district 2 is divided into two subdistricts, designated district 2A and district 2B. For purposes of descriptions of boundaries relating to Brassica seed production district 2, all references to canals pertain to Columbia Basin Irrigation Project structures. Brassica seed production district 2 includes portions of Grant and Adams counties and is bounded as follows:

(a) Beginning at the Grant/Douglas County boundary, the line proceeds continuously due east along existing portions of Road 13NW to its intersection with the West Canal. The line follows the West Canal in a northeasterly direction through portions of the city of Ephrata, then around the northern end of Soap Lake and easterly to the intersection of the West Canal and the East Low Canal. The line follows the East Low Canal in a southerly, then easterly direction to its intersection with State Highway 26. Then it turns west and follows State Highway 26 to the Columbia River. The line continues due west until it intersects the county boundary in the Columbia River. The line then turns north and follows the county boundary to the point of origin.

(b) Brassica seed production district 2A is the northwestern portion of Brassica seed production district 2. It is bounded on the north and west by the boundaries of Brassica seed production district 2. Its eastern boundary line commences at the intersection of Rd. 13 NW and K NW. The line extends south along K NW to its intersection with the I-90 North Frontage Rd. The line extends west along North Frontage Rd. to State Highway 281N, and along State Highway 281N to Q SW. It extends north along Q SW to 5 NW and west along 5 NW to the western boundary of Brassica seed production district 2.

(c) Brassica seed production district 2B consists of the portion of Brassica seed production district 2 that is not encompassed in Brassica seed production district 2A.