Nip′igon, a lake and also a river and a bay, in northwestern Ontario, Canada, through which river and bay the waters of the lake flow to Lake Superior from the north.  The lake lies about 25 miles north of the northernmost part of Lake Superior.  It is 70 miles long from north to south and 45 miles wide from east to west.  It is surrounded by lofty shores, abrupt and precipitous in many places.  Its shores being indented by many bays measure, it is estimated, nearly 600 miles in extent.  It lies about 800 feet above the level of Lake Superior.  Its waters are fed by many mountain streams, and being very deep and cold it is celebrated for the excellence of its fish.  Being thickly studded with islands, it has become a favorite resort for sportsmen and others from the northern United States.  It is said to have in January a mean temperature of but seven degrees above zero, or that of Godthaab in Greenland, and in July the mean temperature of San Francisco.  By some authorities the name is spelled Nepigon.