Transportation is essential to trade, which has always been the backbone of the economy of Thunder Bay, Ontario, Canada, beginning with Fort Kaministiquia in 1717. When the area was first settled its many waterways were used by the voyagers and Coureur des bois to trade their goods. Thunder Bay has a central location within Canada, and is located in the middle of the Trans-Canada Highway system, crossed by railways, and is the location of the largest outbound port on the St. Lawrence Seaway System and the fifth busiest airport in Ontario by aircraft movements.