Northern Ontario is a primary geographic and administrative region of the
Canadian province of
Ontario; the other primary region being
Southern Ontario. The geographic region lies north of
Lake Huron (including
Georgian Bay), the
French River,
Lake Nipissing, and the
Mattawa River, while the administrative region has several boundaries further south that vary according to federal and provincial government policies and requirements. The geographic region (which for
census purposes, includes a part of Nipissing District that lies south of the Mattawa River) has a land area of 802,000 km
2 (310,000 mi
2) and constitutes 87 per cent of the land area of Ontario, although it contains only about six per cent of the population. Most of Northern Ontario is situated on the
Canadian Shield, a vast rocky plateau. The climate is characterized by extremes of
temperature, extremely cold in
winter and hot in
summer. The principal industries are
mining,
forestry, and
hydroelectricity.