The lake is not natural, but rather was created as a reservoir for hydroelectric power generation at the Ontario Power Generation Decew Falls 1 and Decew Falls 2 generating stations.
[3] The lake was created by flooding the shallow valley of Beaverdams Creek.
[3] The lakes form part of the Twelve Mile Creek watershed.
At the west end of the lake is Morningstar Mill, consisting of a working gristmill dating from 1872, plus a reconstructed sawmill.
[5] A short distance east of this are the ruins of DeCou House, the destination of Laura Secord's famous journey during the War of 1812.