Thunder Bay is a city in, and the seat of, Thunder Bay District, Ontario, Canada. It is the most populous municipality in Northwestern Ontario with a population of 108,359 as of the Canada 2011 Census, and the second most populous in Northern Ontario after Greater Sudbury. The census metropolitan area of Thunder Bay has a population of 121,596, and consists of the city of Thunder Bay, the municipalities of Oliver Paipoonge and Neebing, the townships of Shuniah, Conmee, O’Connor, and Gillies, and the Fort William First Nation.
European settlement in the region began in the late 17th century with a French fur trading outpost on the banks of the Kaministiquia River. It grew into an important transportation hub with its port forming an important link in the shipping of grain and other products from western Canada, through the Great Lakes and the Saint Lawrence Seaway, to the east coast. Forestry and manufacturing played important roles in the city’s economy. They have declined in recent years, but have been replaced by a “knowledge economy” based on medical research and education. Thunder Bay is the site of the Thunder Bay Regional Research Institute.
The city takes its name from the immense Thunder Bay at the head of Lake Superior, known on 18th-century French maps as Baie du Tonnerre (Bay of Thunder). The city is often referred to as the “Lakehead”, or “Canadian Lakehead”, because of its location at the end of Great Lakes navigation on the Canadian side of the border.
The city has an area of 328.48 square kilometres, which includes the former cities of Fort William and Port Arthur, as well as the [former] townships of Neebing and McIntyre.
The former Fort William section occupies flat alluvial land along the Kaministiquia River. In the river delta are two large islands: Mission Island and McKellar Island.
The former Port Arthur section is more typical of the Canadian Shield, with gently sloping hills and very thin soil lying on top of bedrock with many bare outcrops. Thunder Bay, which gives the city its name, is about 22.5 kilometres (14.0 mi) from the Port Arthur downtown to Thunder Cape at the tip of the Sleeping Giant.
The city reflects the settlement patterns of the 19th Century and sprawls. Anchoring the west end of the city, the Fort William Town Plot, surveyed in 1859–60, was named West Fort William (or Westfort) in 1888 by the CPR. The land adjoining the lower Kaministiquia River became the residential and central business district of the town and city of Fort William. A large uninhabited area adjoining the Neebing and McIntyre rivers, which became known as Intercity, separated Fort William from the residential and central business district of Port Arthur. At the extreme east of the city, a part of McIntyre Township was annexed to the town of Port Arthur in 1892, forming what later became known as the Current River area.
Since 1970, the central business districts of Fort William and Port Arthur have suffered a serious decline. Business and government relocated to new developments in the Intercity area. There has also been substantial residential growth in adjacent areas of the former Neebing and McIntyre townships.