The Nelson and Kootenay Lake region may be one of the rarest ecosystems on the planet. Sweeping alpine tundra, regal mountain tops and glaciated valleys blanket a unique inland temperate zone, surging with life. Home to ancient forests and iconic keystone species including the grizzly bear and Kokanee salmon, the area feeds species with oceanic affinities. Before the glacier retreated in this area, river ways and large lakes of meltwater provided a path for Sockeye salmon to move from the Pacific Ocean up the Columbia River and into the lakes of the interior, including Kootenay Lake. Ten to twelve thousand years ago, the glacier that shaped the Kootenay Lake retreated and drained away to its current size today, extending up to 150m deep and 4km at its widest point. It is divided into four sections: North End, West Arm, Main Lake and South End. Today, Kootenay Lake is part of a watershed that flows across the international U.S. border and is the largest natural lake in southern British Columbia.