Previous Year Question

The international boundary between Canada and the United States has a total length of approximately 8,891 km. It is the longest international boundary between any two countries in the world.

• It includes approximately 5,061 km of land boundary and 3,830 km of water boundary.

• The boundary has two principal sections:

  1. The boundary between Canada and the contiguous United States.

  2. The boundary between Canada and the US state of Alaska.

• It extends from the St. Croix River near the Atlantic Ocean to the Strait of Juan de Fuca on the Pacific coast, and from the Pacific near Alaska to the Arctic Ocean.

• It passes through four of the five Great Lakes—Superior, Huron, Erie and Ontario.

Why are the other options incorrect?

• Chile–Argentina: Their approximately 5,300-km-long border largely follows the Andes Mountains, but it is shorter than the Canada–US boundary.

• China–India: The boundary between the two countries is not completely demarcated and mutually accepted. The Line of Actual Control—LAC—is a disputed delimitation.

• Kazakhstan–Russia: Their boundary is approximately 7,600 km long and is one of the world’s longest continuous land borders, but its total length is less than the Canada–US boundary.

Fact: The Canada–US boundary consists of two separate sections, whereas the Kazakhstan–Russia border is a continuous land border. Since the question asks only for the “longest border,” Canada–USA is the correct answer.