Kootenay Lake, 407 km2, elev 532 m, is situated in the mountainous southeastern interior of BC. A long, narrow lake squeezed between the Selkirk and Purcell mountain ranges, it is a widening of the Kootenay River, which rises in the Rocky Mountains and flows south into the US before looping sharply north back into Canada. The lake drains west to the Columbia River. The town of Nelson is on the west arm. David Thompson visited in 1808 during one of his fur-trading ventures across the Rockies and found the area occupied by the Kootenay. Late in the century the logging and mining industries moved into this corner of the province. The name derives from a Kootenay word meaning "water people."