The
Canada – United States border, officially known as the
International Boundary, is the longest non-militarized border in the world. The terrestrial boundary (including small portions of maritime boundaries on the
Atlantic,
Pacific, and
Arctic coasts, as well as the
Great Lakes) is 8,891 kilometres (5,525 mi) long, including 2,475 kilometres (1,538 mi) shared with
Alaska. It is Canada's only
land border, and Canada is by far the
largest nation having a land border with only one country.
History

U.S. counties sharing a land or water border with Canada

Sign welcoming drivers into the United States
The present border originated with the
Treaty of Paris in 1783, which ended the war between
Great Britain and the separating colonies which would form the United States. The
Jay Treaty of 1794 created the
International Boundary Commission, which was charged with surveying and mapping the boundary. Westward expansion of both British North America and the United States saw the boundary extended west along the
49th parallel from the
Northwest Angle at
Lake of the Woods to the
Rocky Mountains under the
Convention of 1818. This convention extinguished British claims south of that latitude to the
Red River Valley, which was part of
Rupert's Land. The treaty also extinguished U.S. claims to land north of that line in the watershed of the
Missouri River, which was part of the
Louisiana Purchase; this amounted to only the most northwesterly tip of the Missouri called the
Milk River, in southern Alberta.
Disputes over the interpretation of boundary demarcation led to the
Aroostook War and the ensuing
Webster–Ashburton Treaty in 1842, which better defined the boundary between
Maine and
New Brunswick and the
Province of Canada, as well as the border along the
Boundary Waters in present day
Ontario and
Minnesota between
Lake Superior and the Northwest Angle.
An
1844 boundary dispute during U.S. President
James K. Polk's administration led to a call for the northern boundary of the U.S. west of the Rockies to be
latitude 54° 40' north (related to the southern boundary of
Russia's Alaska Territory), but the
United Kingdom wanted a border that followed the
Columbia River to the Pacific Ocean. The dispute was resolved in the
Oregon Treaty of 1846, which established the
49th parallel as the boundary through the Rockies. The Northwest Boundary Survey (1857–61) laid out the land boundary, but the water boundary was not settled for some time. After the
Pig War in 1859, arbitration in 1872 established the border between the Gulf islands and the
San Juan Islands. In 1903 a joint United Kingdom – Canada – U.S. tribunal established the
boundary with Alaska, much of which follows the
141st meridian west.
International Boundary Commission

The Oregon Country / Columbia District
In 1925, the International Boundary Commission was made a permanent organization responsible for surveying and mapping the boundary, maintaining boundary monuments (and
buoys where applicable), as well as keeping the boundary clear of brush and vegetation for 6 metres (20 ft). This "
boundary vista" extends for 3 metres (10 ft) on each side of the line. The Commission's annual budget is about $1.4 million (USD).
The commission is headed by two commissioners, one of whom is Canadian, the other American. In July 2007, the Bush Administration told the U.S. Commissioner, Dennis Schornack, that he was fired, in connection with a dispute between the boundary commission and the U.S. government over private construction near the border. Schornack rejected the dismissal, saying that the commission is an independent, international organization outside the U.S. government's jurisdiction, and that according to the 1908 treaty that created it, a vacancy can only be created by "the death, resignation or other disability" of a commissioner. The Canadian government said that it was taking no position on the matter, but Peter Sullivan, the Canadian commissioner, said on July 13 that he was ready to work with David Bernhardt, a Colorado-based solicitor of the Department of the Interior, who was designated as the acting U.S. commissioner by President Bush.
Security
Law enforcement approach
The International Boundary is commonly referred to as the world's
longest undefended border, but this is true only in the military sense - law enforcement is present. The relatively low level of security measures stands in contrast to that of the
United States – Mexico border (one-third as long as the Canada–U.S. border), which is actively patrolled by U.S. customs and immigration personnel to prevent illegal migration and drug trafficking.
Parts of the International Boundary cross through mountainous terrain or heavily forested areas, but significant portions also cross remote prairie farmland and the
Great Lakes and
Saint Lawrence River, in addition to the maritime components of the boundary at the
Atlantic,
Pacific, and
Arctic oceans. The border also runs through the middle of the
Akwesasne Nation and even divides some buildings found in communities in Vermont and Quebec whose construction pre-dated the border's delineation.
The actual number of U.S. and Canadian border security personnel is
classified. In comparison, there are in excess of 11,000
United States Border Patrol personnel on the Mexico–U.S. border alone.
Following the
September 11, 2001 terrorist attacks in the United States, border security along the International Boundary was dramatically tightened by both nations in both populated and rural areas. Both nations are also actively involved in detailed and extensive tactical and strategic intelligence sharing. It is a common misconception that the nineteen terrorists involved in the September 11 attacks entered the United States via the Canadian border.
Security measures
Residents of both nations who own property adjacent to the border are required to report construction of any physical border crossing on their land to their respective governments, and this is enforced by the International Boundary Commission. Where required, fences or vehicle blockades are used. All persons crossing the border are required to report to the respective customs and immigration agencies in each country. In remote areas where staffed border crossings are not available, there are hidden
sensors on roads and also scattered in wooded areas near crossing points and on many trails and railways, but there are not enough border personnel on either side to verify and stop coordinated incursions.
Smuggling
In past years Canadian officials have complained of
drug,
cigarette and
firearms smuggling from the United States while U.S. officials have complained of
drug smuggling from Canada. Human smuggling into both countries has been an ongoing problem for border security and law enforcement personnel, although a minor one in comparison to the Mexico–U.S. border.
In July 2005, law enforcement personnel arrested three men who had built a 360-foot (110 m) tunnel under the border between
British Columbia and
Washington that they intended to use for smuggling
marijuana, the first such tunnel known on this border.
Cornwall, Ontario, is central to Canada's most notorious area of smuggling. Its location and transportation links, make it a crossroads for cross-border smuggling of illicit tobacco, illegal aliens, drugs, and firearms. The neighbouring
Mohawk territory of
Akwesasne (which straddles the Ontario-Quebec-New York borders) enjoys a certain "
First Nations" sovereignty which prevents
Ontario Provincial Police and
Royal Canadian Mounted Police from ready access to the source of smuggling operations on the territory. Customs and Excise members from the RCMP’s Northwest and Central regions have even gone to Cornwall to learn about the contraband phenomenon. The smuggling industry is rampant, with collusion between local freelancers, and international organized criminals. Several lives have been lost by civilians as a result of police chasing smugglers; this on top of the hundreds of millions of dollars lost in uncollected government tax, and millions of dollars spent on law enforcement that has had a negligible effect on smuggling .
Western Hemisphere Travel Initiative (WHTI)
The
United States Department of Homeland Security (DHS) enforces rules regarding identification requirements for U.S. citizens and international travellers entering the country. This final rule and first phase of the
Western Hemisphere Travel Initiative establishes four forms of identification—a valid passport, alien registration card,
NEXUS air card, or U.S. military orders—required to enter the US by air.
As of June 2009, all persons arriving through land and sea ports-of-entry (including
ferries) will be required to present a valid passport, enhanced driver's license or a DHS-approved form of identification.
Border lengths
Notable bridge/tunnel crossings
Other border crossings (airports, seaports, rail stations)

Border sign at the Rainbow Bridge, Niagara Falls
The U.S. maintains immigration offices, called "
pre-clearance facilities", in Canadian airports with international air service to the United States (
Calgary,
Edmonton,
Halifax,
Montreal,
Ottawa,
Toronto,
Vancouver, and
Winnipeg). This expedites travel by allowing flights originating in Canada to land at a U.S. airport without being processed as an international arrival. Similar arrangements exist at major Canadian seaports which handle sealed direct import shipments into the United States. Canada does not maintain equivalent personnel at U.S. airports due to the sheer number of destinations served by Canadian airlines and the limited number of flights compared to the number of US-bound flights that depart major Canadian airports. Additionally, at
Vancouver's
Pacific Central Station, passengers are required to pass through U.S. pre-clearance facilities and pass their baggage through an x-ray before being allowed to board the
Seattle-bound
Amtrak Cascades train, which makes no further stops before crossing the border. Pre-clearance facilities are not available for the popular
New York City to
Montreal (
Adirondack) or
Toronto (
Maple Leaf) lines, as these lines have stops between Montreal or Toronto and the border. Instead, passengers must clear customs at a stop located at the actual border.
Several ocean-based
ferry services operate between the provinces of
New Brunswick and
Nova Scotia to the state of
Maine, as well as between the province of
British Columbia and the states of
Washington and
Alaska. There are also several ferry services in the
Great Lakes operating between the province of
Ontario and the states of
Michigan,
New York, and
Ohio.
Cross-border airports
One curiosity on the Canada–US border is the presence of four airports that actually straddle the borderline—
Piney Pinecreek Border Airport in
Manitoba and
Minnesota,
Coronach/Scobey Border Station Airport in
Saskatchewan and
Montana,
Coutts/Ross International Airport in
Alberta and Montana and
Avey Field State Airport in Washington and British Columbia. Each of these airports is adjacent to a border crossing. The runways at Piney Pinecreek and Avey Field run roughly north/south and cross the border; and Coutts/Ross and Coronach/Scobey's runways run east/west, directly along the border itself.
Cross-border buildings
The
Haskell Free Library and Opera House straddles the Canada-US border in
Derby Line, Vermont and
Stanstead, Quebec.
Private homes are divided by the International Boundary line between
Estcourt Station, Maine and
Pohéméganook, Québec.
The Halfway House, a tavern also known as Taillon's International Hotel, straddles the border between
Dundee, Quebec and
Fort Covington, New York. It was built in 1820, before the border was surveyed.
Remaining boundary disputes
See also
- Frozen River, a 2008 feature film about smuggling across the US/Canada border.