Lake Clear lies on the southern edge of the rift valley known as the Ottawa-Bonnechere graben, with the escarpment of the Mount St.Patrick Fault along its south shore having one of the highest elevations in Ontario, approximately 1700'. The lake is one of the largest cold water lakes in the county and has the second longest shoreline of all the Bonnechere watershed lakes, at 46 km. Its deepest point is 46 m, with an average depth of 20 m, and a surface area of 17.4 km². Perhaps the lake's most unique feature is that for such a large lake there are no rivers, inflow comes from 3 small streams and ground water.Geologically, Lake Clear is situated in Precambrian rock of the Grenville Province of the Canadian Shield. Specifically, the lake lies in a very narrow band of Nepheline (primary rock forming mineral) and alkalic syenites, running between Cobden and Bancroft. Turner Island, situated between Green Island and the Twins, was once mined for Berylium, a hard metal.
Lake Clear has approximately a dozen islands that with the exception of two are accessible to the public. Four are owned by the Lake Clear Conservancy (LCC) and the others by the Crown.
In 1999, the LCC had Renfrew County biologist Chris Michener do an inventory of the flora and fauna of three of its islands - Green and the two Twins.
Why are these islands important?
Collectively the islands represent the largest amount of public accessible land on the lake. Three of the islands: Blueberry, Haines and Muddy provide 7 public campsites. The biodiversity of the islands makes them interesting places to visit for those interested in nature. Green Island has the most diverse flora resulting from a major forest fire in the 1950s.
All the islands have long been valued for their beauty and recreational use and over the years many volunteers have engaged in various stewarding activities such as the planting of nearly 1,000 trees and on managing 7 public campsites.
In 1999, the Lake Clear Conservancy was created to protect the natural heritage features of Green and the two Twin Islands and since then also Lornie Foran Island.
Visit Lake Clear's Special Natural Areas
Lake Clear Conservancy's Conservation Reserves:
Lornie Foran Island
Crown Islands and forest
Blueberry, Haines and Muddy Islands campsites
Frenches and several smaller islands
Old growth forest