7 C.F.R. § 1030.2
The marketing area means all territory within the bounds of the following states and political subdivisions, including all piers, docks, and wharves connected therewith and all craft moored thereat, and all territory occupied by government (municipal, State, or Federal) reservations, installations, institutions, or other similar establishments if any part thereof is within any of the listed states or political subdivisions:
Illinois Counties
Boone, Carroll, Cook, De Kalb, Du Page, Jo Daviess, Kane, Kendall, Lake, Lee, McHenry, Ogle, Stephenson, Will, and Winnebago.
Iowa Counties
Howard, Kossuth, Mitchell, Winnebago, Winneshiek, and Worth.
Michigan Counties
Delta, Dickinson, Gogebic, Iron, Menominee, and Ontonagon.
Minnesota
All counties except Lincoln, Nobles, Pipestone, and Rock.
North Dakota Counties
Barnes, Cass, Cavalier, Dickey, Grand Forks, Griggs, La Moure, Nelson, Pembina, Ramsey, Ransom, Richland, Sargent, Steele, Traill, and Walsh.
South Dakota Counties
Brown, Day, Edmunds, Grant, Marshall, McPherson, Roberts, and Walworth.
Wisconsin Counties
All counties except Crawford and Grant.
7 C.F.R. § 1030.2