The lands surrounding the lake are part of the Canadian Shield, one of the largest single exposure of Precambrian rocks in the world which were formed after the Earth's crust cooled.

The hills in the Temagami area are remnants of the oldest mountain ranges in North America, that date back to the Precambrian era.

The uplifting was accomplished as enormous pressure caused the earth to buckle in a process called folding.

Other processes, such as volcanic activity and geologic faulting in which the earth cracks open also contributed to the formation of these mountains.

The Temagami area also contains some pillow lava about 2 billion years old, indicating that great submarine volcanoes existed during the early stages of the formation of the Earth's crust.

The northeast arm of Lake Temagami is underlain by a strong fault zone of sheared felsic to intermediate metavolcanic rocks that is approximately 1,200 m (3,900 ft) wide.

The region contains some of the largest remaining stands of old growth red and white pine forests in Ontario.

In 1834, the Hudson's Bay Company opened a fur trading post on the lake, which operated during the 19th century.

Since it began running trips in Ontario in 1902, it is the earliest known private business on Temagami besides for the HBC post on Bear Island.

[1] While Camp Temagami emphasized the importance of the wilderness canoe trip for shaping young men, the camp also developed a robust in-camp program that included athletics and life-guard training, as well as the study of the natural environment and Native American folklore.

[2] Camp Temagami offered canoe trips and in-camp activities for boys and young men until its closure in 1972.

[4] Lake Temagami’s vacation lodges and canoe tripping camps flourished during the early interwar years.

Appleby College's northern campus is located on Rabbit Nose island, opened in the mid 1970s it provides a launching point for their Northward Bound program which takes place in January, February, May and June.