The Natural Setting of the Township of the Rideau Lakes is highlighted by the rugged Frontenac Axis, a branch of the Canadian Shield with its ancient metamorphic rocks and igneous granite, baked and blended in the roots of the Grenville Mountains a billion years ago. Within those rocks are a diversity of minerals found nowhere else in the world. Through time, rain and wind, rivers and glaciers have worn away these peaks to their very roots. Paleozoic seas washed over this rugged land half a billion years ago and left beautiful layers of sandstone; the kind used locally for building the Rideau Canal locks and dams.
Only thousands of years ago, Ice Ages gouged out patches of soft Precambrian marble leaving basins for our numerous lakes and buffering their waters against acid rain. Hard Precambrian granite and quartzite resisted the grinding of glaciers and formed countless rugged hills such as Foley and Willow Mountains. The melting of the most recent ice sheet a mere ten thousand years ago left us a rich legacy of fertile lake clays and sandy and gravelly beaches.