The FCC Rules governing use of the General Mobile Radio Service (GMRS) include restrictions (47 CFR 95.45, which also references 47 CFR 1.923 and 1.924) on the use of certain frequencies by certain classes of stations when operating "north of Line A" and "east of Line C" (i.e., near the US/Canadian borders).
The FCC imposes restrictions on most GMRS licenses that prohibit the licensee from operating his/her stations north of Line A or east of Line C on certain GMRS frequencies (primarily: 462.650 MHz, 462.700 MHz, 467.650 MHz, and 467.700 MHz).
There is a treaty definition of Lines A and C. The FCC has also posted a map of these lines, but the map lacks sufficient detail to answer some questions about operation in specific areas or along certain major highways.
Below are described, on a state-by-state basis, the areas that are north of Line A (or east of Line C in Alaska). This includes:
If you find errors in this list, or if you wish to recommend other changes, please contact PRSG.
There are portions of 18 states included in the Line A and Line C areas. Select your state of interest from the following list:
| Alaska | Maine | Montana | North Dakota | Vermont |
| Idaho | Michigan | New Hampshire | Ohio | Washington |
| Indiana | Minnesota | New York | Pennsylvania | Wisconsin |
Treaty definition (for east of Line C): The area east of the line from the intersection of latitude 70 degrees N and longitude 144 degrees W, by great circle arc to the intersection of latitude 60 degrees N and longitude 143 degrees W.
In general: The area within 75 miles of the US/Canadian border, plus all of the Alaskan Panhandle. This includes the following major highways:
Treaty definition: The area north of the latitude 48 degrees N (approximately 72 miles south of the US/Canadian border).
In general: All areas north of the southern tip of Lake Pend Oreille. This includes the following major highways:
Treaty definition: The area east of longitude 85 degrees W (approximately 10 miles east of the Indiana/Ohio border) and north of latitude 41 degrees N (approximately 5 miles south of the center of Fort Wayne, IN).
In general: The area within 10 miles of the Indiana/Ohio border, and within 53 miles of the Indiana/Michigan border. This includes the following major highways:
This includes portions or all of the following Indiana counties: Allen, De Kalb, Steuben
Treaty definition: The area north of a line from latitude 41 degrees N, longitude 82 degrees W (near Lodi, OH) by great circle arc to Bangor, ME. Then by great circle arc to Searsport, ME.
In general, the northern two-thirds of the state. This includes the following major highway:
This includes portions or all of the following Maine counties: Aroostook, Franklin, Hancock, Kennebec, Oxford, Penobscot, Piscataquis, Somerset, Waldo, Washington
Treaty definition: The area north and east of a line from the southern-most point of Duluth, MN, via great circle arc to latitude 45 degrees N, longitude 85 degrees W (about 5 miles north of Mancelona), then south along longitude 85 degrees to the Michigan/Indiana border.
In general: This includes nearly all of the Upper Peninsula (except the southern tip), and those portions of the Lower Peninsula east of a north/south line through Ionia (about midway between Lansing and Grand Rapids).
In the Upper Peninsula, this includes all major highways except US 41 from the junction of US 2 south to the Michigan/Wisconsin border.
In the Lower Peninsula, this includes the following major highways:
This includes portions or all of the following Michigan counties: Alcona, Alger, Alpena, Antrim, Arenac, Baraga, Bay, Branch, Calhoun, Charlevoix, Cheboygan, Chippewa, Claire, Clinton, Crawford, Delta, Dickinson, Eaton, Emmett, Genesee, Gladwin, Gogebic, Gratiot, Hillsdale, Houghton, Huron, Ingham, Ionia, Iosco, Iron, Isabella, Jackson, Kalkaska, Keweenaw, Lapeer, Leelanau, Lenawee, Livingston, Luce, Mackinac, Macomb, Marquette, Menominee, Midland, Missaukee, Monroe, Montcalm, Montmorency, Oakland, Ogemaw, Ontonagon, Oscoda, Otsego, Presque Isle, Roscommon, Saginaw, Sanilac, Schoolcraft, Shiawassee, St. Clair, Tuscola, Washtenaw, Wayne
Treaty definition: The area north of latitude 48 degrees N (approximately 75 miles south of the US/Canadian border), plus the area north of a great circle arc from the intersection of latitude 48 degrees N and longitude 95 degrees W (about 5 miles north of Mancelona, MI) west through the southern end of Duluth.
In general: the northern quarter of the state. This includes the following major highways:
This includes portions or all of the following Minnesota counties: Beltrami, Carlton, Clearwater, Cook, Itasca, Kittson, Koochiching, Lake, Lake of the Woods, Marshall, Pennington, Polk, Roseau, St. Louis
Treaty definition: The area north of latitude 48 degrees N (approximately 75 miles south of the US/Canadian border).
In general: the northern quarter of the state. This includes the following major highways:
This area includes portions or all of the following Montana counties: Blaine, Chouteau, Daniels, Flathead, Glacier, Hill, Lake, Liberty, Lincoln, McCone, Phillips, Pondera, Richland, Roosevelt, Sanders, Teton, Toole, Valley
Treaty definition: The area north of a line from the junction of latitude 41 degrees N and longitude 82 degrees W (near Lodi, OH) by great circle arc to Bangor, Maine.
In general: the northern half of the state. This area includes the following major highway:
This area includes portions or all of the following New Hampshire counties: Carroll, Coos, Grafton
Treaty definition: The area north of a line from the junction of latitude 41 degrees N and longitude 82 degrees W (near Lodi, OH) by great circle arc to Bangor, Maine.
In general: only the far northwestern corner of the state. This area includes the following major highways:
This area includes portions or all of the following New York counties: Alleghany, Cattaraugus, Cayuga, Chautaugua, Clinton, Erie, Essex, Franklin, Genesee, Hamilton, Herkimer, Jefferson, Lewis, Livingston, Madison, Monroe, Niagara, Oneida, Onondaga, Ontario, Orleans, Oswego, Seneca, Steuben, St. Lawrence, Warren, Washington, Wayne, Wyoming, Yates
Treaty definition: The area north of latitude 48 degrees N (approximately 75 miles south of the US/Canadian border).
In general: the northern third of the state. This includes the following major highways:
This area includes portions or all of the following North Dakota counties: Benson, Bottineau, Burke, Cavalier, Divide, Grand Forks, McHenry, McKenzie, Mountrail, Nelson, Pembina, Pierce, Ramsey, Renville, Rolette, Towner, Walsh, Ward, Williams
Treaty definition: The area north of latitude 41 degrees N from the Indiana line east to longitude 82 degrees W (near Lodi, OH), and north by great circle arc to Bangor, Maine.
In general, the northern quarter of the state. This includes the following major highways:
This includes portions or all of the following Ohio counties: Ashland, Ashtabula, Cuyahoga, Defiance, Erie, Fulton, Geauga, Hancock, Henry, Huron, Lake, Lorain, Lucas, Medina, Ottawa, Paulding, Portage, Putnam, Sandusky, Seneca, Summit, Trumbull, Williams, Woods
Treaty definition: The area north of a line from the junction of latitude 41 degrees N and longitude 82 degrees W (near Lodi, OH), and north by great circle arc to Bangor, Maine.
In general: only the far northwestern corner of the state. This area includes the following major highways
This includes portions or all of the following Pennsylvania counties: Crawford, Erie, Warren
Treaty definition: The area north of a line from the junction of latitude 41 degrees N and longitude 82 degrees W (near Lodi, OH), and north by great circle arc to Bangor, Maine.
In general: the northern two-thirds of the state. This area includes the following major highways:
This area includes portions or all of the following Vermont counties; Addison, Caledonia, Chittenden, Essex, Franklin, Grand Isle, Lamoille, Orange, Orleans, Rutland, Washington, Windsor
Treaty definition: The area north of a line from Aberdeen, by great circle arc to the intersection of latitude 48 degrees N, longitude 120 degrees W (near Methow, WA), then along latitude 48 degrees N.
In general: the northern 40% of the state. This includes the following major highways:
This includes portions or all of the following Washington counties: Chelan, Clallam, Douglas, Ferry, Grays Harbor, Island, Jefferson, King, Kitsap, Mason, Okanogan, Pend Oreille, Pierce, San Juan, Skagit, Snohomish, Spokane, Stevens, Whatcom
Treaty definition: The area north of a line from the southern most point of Duluth, by great circle arc to the junction of latitude 45 degrees N and longitude 85 degrees W (about 5 miles north of Mancelona, MI).
In general: only the northern fringe of the state. This includes the following major highway:
This area includes portions or all of the following Wisconsin counties: Ashland, Bayfield, Douglas, Florence, Forest, Iron, Vilas