Canada–United States border

Canada–United States border
The Peace Arch at the border between Surrey, British Columbia, and Blaine, Washington
Characteristics
Entities	Canada  United States
Length	8,891 km (5,525 mi)
History
Established	September 3, 1783 Signing of the Treaty of Paris at the end of the American War of Independence
Current shape	April 11, 1908 Treaty of 1908
Treaties	Treaty of Paris Jay Treaty Treaty of 1818 Webster–Ashburton Treaty Oregon Treaty
Notes	See list of current disputes

v t e Canada–United States border
Legend
Arctic Ocean Beaufort Sea Continental Divide Arctic Basin Pacific Basin Porcupine River Arctic Circle Yukon River Poker Creek–Little Gold Creek Alcan–Beaver Creek Yukon British Columbia Dalton Cache–Pleasant Camp Skagway–Fraser White Pass and Yukon Route Hyder–Stewart Ketchikan (AMH) Portland Canal Alaska Marine Highway Dixon Entrance Alaska, United States British Columbia, Canada Prince Rupert (AMH) British Columbia, Canada Washington, United States Strait of Juan de Fuca Port Angeles–Victoria Ferry Puget Sound Seattle–Victoria Ferry Haro Strait Friday Harbor–Sidney Ferry Anacortes–Sidney Ferry Boundary Pass Bellingham (AMH) Strait of Georgia Point Roberts–Boundary Bay Boundary Bay Amtrak Cascades Peace Arch Border Crossing Pacific Highway Border Crossing Lynden–Aldergrove Sumas–Huntingdon Nighthawk–Chopaka Ross Lake Silver Skagit Road Pacific Crest Trail Pasayten River Oroville–Osoyoos Osoyoos Lake Ferry–Midway Danville–Carson Laurier–Cascade Frontier–Paterson Columbia River Boundary–Waneta Pend Oreille River Metaline Falls–Nelway Washington Idaho Kootenay River Porthill-Rykerts Eastport–Kingsgate Idaho Montana Lake Koocanusa Eureka–Roosville North Fork Flathead River Continental Divide Pacific Basin | British Columbia Hudson Bay Basin | Alberta Continental Divide Trail Waterton Lake Chief Mountain Border Crossing Piegan–Carway St. Mary River Laurentian Divide Hudson Bay Basin Gulf of Mexico Basin Del Bonita Border Crossing Milk River Sweetgrass–Coutts Whitlash–Aden Milk River Wild Horse Border Crossing Alberta Saskatchewan Willow Creek Border Crossing Turner–Climax Morgan–Monchy Opheim–West Poplar River Scobey–Coronach Raymond–Regway Montana North Dakota Fortuna–Oungre Laurentian Divide Gulf of Mexico Basin Hudson Bay Basin Ambrose–Torquay Noonan–Estevan Highway Portal–North Portal Northgate Border Crossing Souris River Sherwood–Carievale Saskatchewan Manitoba Antler–Lyleton Westhope–Coulter Souris River Carbury–Goodlands Dunseith–Boissevain St. John–Lena Hansboro–Cartwright Sarles–Crystal City Hannah–Snowflake Maida–Windygates Walhalla–Winkler Neche–Gretna Pembina–Emerson Red River of the North North Dakota Minnesota Lancaster–Tolstoi Pinecreek–Piney Roseau–South Junction Warroad–Sprague Lake of the Woods Northwest Angle Manitoba Ontario Rainy River Baudette–Rainy River International Falls–Fort Frances Rainy Lake Kettle Falls Dam Namakan Lake Sand Point Lake Little Vermillion Lake Loon River Loon Lake Lac La Croix Bottle River Bottle Lake Iron Lake Crooked Lake Basswood River Basswood Lake Sucker Lake Birch Lake Carp Lake Knife River Knife Lake Ottertrack Lake Monument Portage Swamp Lake Saganaga Lake Maraboeuf Lake Gneiss Lake Granite River Clove Lake Pine River Magnetic Lake Gunflint Lake Little Gunflint Lake Little North Lake North Lake Height of Land Portage over the Laurentian Divide Hudson Bay Basin St. Lawrence Basin South Lake Rat Lake Rose Lake Arrow River Rove Lake Watap Lake Watap Portage Mountain Lake Pigeon River Moose Lake Fowl Lake Pigeon River Grand Portage–Pigeon River Lake Superior Minnesota Michigan St. Marys River Sault Sainte Marie Border Crossing Soo Locks Lake Huron St. Clair River Port Huron–Sarnia Walpole–Algonac Ferry Lake St. Clair Detroit River Detroit–Windsor tunnel Ambassador Bridge Detroit–Windsor Truck Ferry Lake Erie Michigan Ohio Sandusky–Pelee Ferry Ohio Pennsylvania Pennsylvania New York Niagara River Peace Bridge Horseshoe Falls (Niagara Falls) Rainbow Bridge Whirlpool Rapids Bridge Maple Leaf Lewiston–Queenston Bridge Lake Ontario Cape Vincent–Wolfe Island Ferry St. Lawrence River Thousand Islands Border Crossing Ogdensburg–Prescott Three Nations Crossing Ontario Quebec Fort Covington–Dundee Trout River Border Crossing Chateaugay–Herdman Churubusco–Franklin Centre Cannon Corners–Covey Hill Mooers–Hemmingford Champlain–St. Bernard de Lacolle Overton Corners–Lacolle 221 Adirondack Rouses Point–Lacolle 223 Lake Champlain New York Vermont Alburgh–Noyan Montrealer Discontinued / Proposed Alburg Springs–Clarenceville Missisquoi Bay Highgate Springs– St. Armand/Philipsburg Morses Line Border Crossing West Berkshire–Frelighsburg Pinnacle Road–East Pinnacle Richford–Abercorn East Richford–Glen Sutton North Troy–Highwater Lake Memphremagog Beebe Plain–Beebe Derby Line–Stanstead Derby Line–Rock Island Norton–Stanhope St. Lawrence River Divide St. Lawrence Basin Atlantic Basin Canaan–Hereford Road Beecher Falls–East Hereford Halls Stream Vermont New Hampshire Pittsburg–Chartierville New Hampshire Maine Coburn Gore–Woburn Armstrong–Jackman St. Zacharie Border Crossing Little Saint John Lake Southwest Branch Saint John River St. Aurelie Maine–St. Aurelie Saint Just de Bretenières– St. Juste Maine Saint Pamphile Border Crossing Estcourt Station–Pohénégamook Saint Francis River Quebec New Brunswick Saint John River Fort Kent–Clair Madawaska–Edmundston Van Buren–St. Leonard Hamlin–Grand Falls Limestone - Gillespie Portage Four Falls Border Crossing Aroostook River Fort Fairfield–Andover Easton–River de Chute Bridgewater–Centreville Monticello–Bloomfield Houlton–Woodstock Monument Brook North Lake North Lake Thoroughfare Grand Lake Orient–Fosterville Forest City Stream Forest City Border Crossing Mud Lake Mud Lake Stream Spednic Lake St. Croix River Vanceboro–St. Croix Grand Falls Dam Woodland Dam International Avenue Border Crossing Calais–Milltown Ferry Point Border Crossing Passamaquoddy Bay Western Passage Eastport–Deer Island Ferry Lubec Narrows Lubec–Campobello Grand Manan Channel Bay of Fundy New Brunswick Nova Scotia Bar Harbor–Yarmouth Ferry Gulf of Maine Atlantic Ocean

The international border between Canada and the United States is the longest in the world by total length.^[a] The boundary (including boundaries in the Great Lakes, Atlantic, and Pacific coasts) is 8,891 km (5,525 mi) long. The land border has two sections: Canada's border with the northern tier of the contiguous United States to its south, and with the U.S. state of Alaska to its west. The bi-national International Boundary Commission deals with matters relating to marking and maintaining the boundary, and the International Joint Commission deals with issues concerning boundary waters. The agencies responsible for facilitating legal passage through the international boundary are the Canada Border Services Agency (CBSA) and U.S. Customs and Border Protection (CBP).

The Treaty of Paris of 1783 ended the American Revolutionary War between Great Britain and the United States. In the second article of the Treaty, the parties agreed on all boundaries of the United States, including, but not limited to, the boundary to the north along what was then British North America. The agreed-upon boundary included the line from the northwest angle of Nova Scotia to the northwesternmost head of the Connecticut River and proceeded down along the middle of the river to the 45th parallel of north latitude.

The parallel had been established in the 1760s as the boundary between the provinces of Quebec and New York (including what would later become the State of Vermont). It was surveyed and marked by John Collins and Thomas Valentine from 1771 to 1773.