query: How long is the Canadian-US border?
passage: Canada–United States border
The Canada–United States border (French: frontière Canada–États-Unis), officially known as the International Boundary (French: Frontière Internationale), is the longest international border in the world between two countries. It is shared between Canada and the United States, the second- and fourth-largest countries by area, respectively. The terrestrial boundary (including portions of maritime boundaries in the Great Lakes, and on the Atlantic, Pacific, and Arctic coasts) is 8,891 kilometres (5,525mi) long, of which 2,475 kilometres (1,538mi) is Canada's border with Alaska. Eight Canadian provinces and territories (Yukon, British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, Quebec, and New Brunswick), and thirteen U.S. states (Alaska, Washington, Idaho, Montana, North Dakota, Minnesota, Michigan, Ohio, Pennsylvania, New York, Vermont, New Hampshire, and Maine) are located along the border.
passage: Canada–United States border
Rail crossings: There are 39 railroads that cross the US–Canada border. Nine of these are no longer in use. Eleven of them cross the border at bridges or tunnels. Only four international rail lines currently carry passengers between the US and Canada.