Areas regulated under the rough bluegrass quarantine include all counties in the state of Washington lying east of the Cascade Crest.

(1) This quarantine shall not apply to:

(a) Experiments or trial grounds of the United States Department of Agriculture;

(b) Experiments or trial grounds of Washington State University experiment station; or

(c) Trial grounds of any person, firm, or corporation except that the trial ground plantings are approved by the director and under supervision of trained personnel familiar with rough bluegrass control.

(2) This quarantine shall not apply to seed production fields of rough bluegrass grown in Yakima County and that part of Benton County that lies within the Yakima River drainage.