Interstate movement of rust-susceptible Berberis, Mahoberberis, or Mahonia into or through protected areas is prohibited, except with a limited permit (which is issued under certain circumstances, as described in the regulations). State officials within the protected areas are responsible for issuing the certificates required for interstate movement, and for inspecting every plant nursery within the State at least once each year to ensure that they are free of rust-susceptible plants (7 CFR Part 301.38-3). (For map of "protected areas".)

Protected Areas

Illinois
Indiana
Iowa
Kansas
Michigan
Minnesota
Missouri
Montana
Nebraska
North Dakota
Ohio
Pennsylvania
South Dakota
West Virginia
Wisconsin
Wyoming

Also the following counties in the state of Washington:

Adams
Asotin
Benton
Chelan
Columbia
Douglas
Ferry
Franklin
Garfield
Grant
Kittitas
Klickitat
Lincoln
Okanogan
Pend Oreille
Spokane
Stevens
Walla Walla
Whitman
Yakima