Thirteen U.S. states border Canada: Alaska, Washington, Idaho, Montana, North Dakota, Minnesota, Michigan, Ohio, Pennsylvania, New York, Vermont, New Hampshire, and Maine.
Together, these states form the American side of the Canada–United States boundary, which stretches approximately 5,525 miles (8,891 kilometers) from the Atlantic to the Pacific and then north along Alaska to the Arctic Ocean. The International Boundary Commission records roughly 3,145 miles of the boundary on land and 2,380 miles on water.
Not every state actually touches Canada on land. Michigan, Ohio, and Pennsylvania share their international boundaries with Canada across the Great Lakes and connecting waterways.
Which States Border Canada?
Here are the 13 states that border Canada, arranged generally from west to east.
| U.S. State | Canadian Province or Territory | Border Length |
|---|---|---|
| Alaska | Yukon, British Columbia | 1,538 miles |
| Washington | British Columbia | 427 miles |
| Idaho | British Columbia | 45 miles |
| Montana | British Columbia, Alberta, Saskatchewan | 545 miles |
| North Dakota | Saskatchewan, Manitoba | 310 miles |
| Minnesota | Manitoba, Ontario | 547 miles |
| Michigan | Ontario | 721 miles |
| Ohio | Ontario | 146 miles |
| Pennsylvania | Ontario | 42 miles |
| New York | Ontario, Quebec | 445 miles |
| Vermont | Quebec | 90 miles |
| New Hampshire | Quebec | 58 miles |
| Maine | Quebec, New Brunswick | 611 miles |
Border lengths are based on measurements published by the International Boundary Commission.
1. Alaska
Canadian neighbors: Yukon and British Columbia
Border length: 1,538 miles
Alaska has the longest border with Canada of any U.S. state.
Its Canadian boundary stretches for approximately 1,538 miles, or 2,475 kilometers. Much of it runs through remote mountains, forests, glaciers, and sparsely populated wilderness.
Alaska is also the only U.S. state that borders Canada’s Yukon Territory.
The northern portion of the boundary follows the 141st meridian for a considerable distance before the border becomes much more irregular in southeastern Alaska.
2. Washington
Canadian neighbor: British Columbia
Border length: 427 miles
Washington shares approximately 427 miles of international boundary with British Columbia.
Much of the border follows the 49th parallel. The state’s location makes it an important gateway between the Pacific Northwest and western Canada.
The Vancouver, British Columbia, and Seattle, Washington, metropolitan areas are also relatively close to one another, making this one of the better-known sections of the international boundary.
3. Idaho
Canadian neighbor: British Columbia
Border length: 45 miles
Idaho has one of the shortest borders with Canada.
Only the narrow northern part of the state, known as the Idaho Panhandle, reaches the international boundary. Idaho meets British Columbia for approximately 45 miles.
Only Pennsylvania has a slightly shorter Canadian boundary.
4. Montana
Canadian neighbors: British Columbia, Alberta, and Saskatchewan
Border length: 545 miles
Montana shares approximately 545 miles of border with Canada.
It is especially notable because it borders three Canadian provinces: British Columbia, Alberta, and Saskatchewan.
The western portion of the border passes through mountainous terrain, while the eastern section crosses the open landscapes of the Great Plains.
5. North Dakota
Canadian neighbors: Saskatchewan and Manitoba
Border length: 310 miles
North Dakota shares approximately 310 miles of international boundary with Saskatchewan and Manitoba.
Like much of the border across the northern Great Plains, the boundary here largely follows the 49th parallel.
North Dakota’s relatively flat terrain makes the international line appear unusually straight on most maps.
6. Minnesota
Canadian neighbors: Manitoba and Ontario
Border length: 547 miles
Minnesota shares approximately 547 miles of boundary with Canada.
Its border is much more geographically complex than the straight international boundary farther west. Lakes, rivers, islands, and forests shape much of Minnesota’s northern edge.
The unusual Northwest Angle is also found here. This small section of Minnesota extends north of the 49th parallel and is separated from the rest of the contiguous United States by land unless travelers pass through Canada.
7. Michigan
Canadian neighbor: Ontario
Border length: 721 miles
Michigan shares approximately 721 miles of international boundary with Ontario, giving it the second-longest Canada border of any U.S. state after Alaska.
Unlike most border states, however, Michigan’s international boundary lies along water.
The boundary passes through the Great Lakes and connecting waterways, including the St. Marys River, St. Clair River, Detroit River, and surrounding lakes.
Despite the water boundary, Michigan and Ontario are directly connected by major bridges and a tunnel. These include the Blue Water Bridge, Ambassador Bridge, Detroit Windsor Tunnel, and the International Bridge at Sault Ste. Marie.
8. Ohio
Canadian neighbor: Ontario
Border length: 146 miles
Ohio borders Canada across Lake Erie.
The state’s international boundary is approximately 146 miles long, but Ohio has no land boundary with Canada.
Ontario lies on the opposite side of the lake.
This is one reason Ohio is sometimes accidentally excluded from informal lists of states bordering Canada. Politically and geographically, however, the international boundary through Lake Erie makes Ohio a Canadian border state.
9. Pennsylvania
Canadian neighbor: Ontario
Border length: 42 miles
Pennsylvania has the shortest border with Canada of any U.S. state, measuring approximately 42 miles.
Like Ohio, Pennsylvania’s Canadian boundary exists entirely across Lake Erie.
The border lies off the state’s relatively short Lake Erie shoreline in northwestern Pennsylvania.
Because there is no land connection between Pennsylvania and Canada, it is another state that people frequently overlook when naming Canadian border states.
10. New York
Canadian neighbors: Ontario and Quebec
Border length: 445 miles
New York shares approximately 445 miles of international boundary with Canada.
It borders both Ontario and Quebec.
Unlike the straight borders of the Great Plains, New York’s boundary includes major waterways. Portions pass through the Great Lakes, Niagara River, St. Lawrence River, and other water features before reaching the land boundary with Quebec.
The Niagara Falls region is one of the most recognizable locations along the entire U.S.–Canada boundary.
11. Vermont
Canadian neighbor: Quebec
Border length: 90 miles
Vermont shares approximately 90 miles of border with Quebec.
The border forms the state’s northern edge and connects rural communities in Vermont with southern Quebec.
Unlike neighboring New York and Maine, Vermont borders only one Canadian province.
12. New Hampshire
Canadian neighbor: Quebec
Border length: 58 miles
New Hampshire has approximately 58 miles of border with Quebec.
Only Idaho and Pennsylvania have shorter Canadian boundaries.
The international boundary lies at the far northern end of New Hampshire, well beyond the state’s larger population centers in the south.
13. Maine
Canadian neighbors: Quebec and New Brunswick
Border length: 611 miles
Maine shares approximately 611 miles of border with Canada, giving it the third-longest Canadian boundary among U.S. states after Alaska and Michigan.
It borders Quebec to the northwest and New Brunswick to the north and east.
Maine also has the longest Canada boundary among the states of New England.
Its border follows a mixture of forests, rivers, lakes, and surveyed boundary lines before reaching the Atlantic region.
How Many U.S. States Share a Land Border With Canada?
The distinction between a border and a land border is important.
All 13 states listed above share an international boundary with Canada.
However, three of them have their Canadian boundary entirely across water:
- Michigan
- Ohio
- Pennsylvania
Michigan is somewhat unusual because major bridges and a tunnel physically connect it with Ontario even though the international boundary beneath those crossings follows waterways.
Ohio and Pennsylvania meet Canada across Lake Erie and have no direct road bridge or tunnel into Canada.
This distinction explains why some lists incorrectly give different answers when asking how many states border Canada.
Which State Has the Longest Border With Canada?
Alaska has the longest U.S. state border with Canada at approximately 1,538 miles.
Michigan ranks second at about 721 miles, although its boundary with Ontario follows waterways.
Maine has approximately 611 miles of Canadian boundary.
According to International Boundary Commission measurements, the five longest state boundaries with Canada are:
| Rank | State | Canada Border Length |
|---|---|---|
| 1 | Alaska | 1,538 miles |
| 2 | Michigan | 721 miles |
| 3 | Maine | 611 miles |
| 4 | Minnesota | 547 miles |
| 5 | Montana | 545 miles |
Which State Has the Shortest Border With Canada?
Pennsylvania has the shortest international boundary with Canada at approximately 42 miles.
Its entire Canadian boundary lies within Lake Erie.
The next shortest are:
- Idaho, 45 miles
- New Hampshire, 58 miles
- Vermont, 90 miles
What Canadian Provinces and Territories Border the United States?
Eight Canadian provinces and territories border the United States:
| Canadian Province or Territory | U.S. States It Borders |
|---|---|
| Yukon | Alaska |
| British Columbia | Alaska, Washington, Idaho, Montana |
| Alberta | Montana |
| Saskatchewan | Montana, North Dakota |
| Manitoba | North Dakota, Minnesota |
| Ontario | Minnesota, Michigan, Ohio, Pennsylvania, New York |
| Quebec | New York, Vermont, New Hampshire, Maine |
| New Brunswick | Maine |
Ontario has the longest boundary with the United States among Canadian provinces and territories, measuring approximately 1,715 miles, according to the International Boundary Commission.
How Long Is the U.S.–Canada Border?
The international boundary between the United States and Canada is approximately 5,525 miles, or 8,891 kilometers, long.
The International Boundary Commission divides it into two main sections.
The boundary from the Atlantic Ocean to the Pacific Ocean measures about 3,987 miles. The Alaska–Canada section from the Pacific region to the Arctic measures another 1,538 miles.
Taken together, approximately:
- 3,145 miles are on land
- 2,380 miles are on water
- 5,525 miles make up the complete boundary
The border also crosses four of the five Great Lakes. Lake Michigan is the only Great Lake located entirely within the United States.
Why Does the U.S.–Canada Border Follow the 49th Parallel?
A large section of the western U.S.–Canada boundary follows the 49th parallel north.
The international boundary developed through several treaties and agreements rather than being established all at once.
The International Boundary Commission traces its development back to agreements including the 1783 Treaty of Paris, the Convention of 1818, and the Oregon Treaty of 1846. Later surveys and agreements clarified and marked different sections of the boundary.
Today, the straight line of the 49th parallel is particularly easy to see on maps across parts of Washington, Idaho, Montana, North Dakota, and Minnesota.
The Bottom Line
There are 13 states that border Canada, stretching from Alaska in the northwest to Maine in the northeast.
Alaska has the longest Canadian boundary at 1,538 miles, while Pennsylvania has the shortest at 42 miles. The geography is more complicated than a simple line on a map because a substantial part of the international boundary runs through rivers and lakes.
That is why Michigan, Ohio, and Pennsylvania still count among the 13 border states even though their boundaries with Canada are entirely on water.
Frequently Asked Questions
There are 13 U.S. states that border Canada: Alaska, Washington, Idaho, Montana, North Dakota, Minnesota, Michigan, Ohio, Pennsylvania, New York, Vermont, New Hampshire, and Maine.
The 13 states are Alaska, Washington, Idaho, Montana, North Dakota, Minnesota, Michigan, Ohio, Pennsylvania, New York, Vermont, New Hampshire, and Maine.
Alaska has the longest border with Canada at approximately 1,538 miles.
Pennsylvania has the shortest boundary with Canada at approximately 42 miles, entirely within Lake Erie.
Yes. Michigan shares approximately 721 miles of international boundary with Ontario. The boundary follows the Great Lakes and connecting waterways, while several bridges and a tunnel provide direct transportation links between Michigan and Ontario.
Yes. Ohio shares approximately 146 miles of international boundary with Ontario across Lake Erie. It does not have a land border with Canada.
Yes. Pennsylvania shares approximately 42 miles of boundary with Ontario across Lake Erie, making it the U.S. state with the shortest Canadian border.
Michigan, Ohio, and Pennsylvania have international boundaries with Canada that lie entirely along water. Portions of several other states, including Minnesota and New York, also follow lakes or rivers.
Montana borders three Canadian provinces: British Columbia, Alberta, and Saskatchewan. No other U.S. state borders more than three.
The international boundary passes through Lake Superior, Lake Huron, Lake Erie, and Lake Ontario. Lake Michigan lies completely within the United States.
