[1] Fed primarily by springs in the surrounding swamps, it is the source of the Wisconsin River, which flows out of its southwest corner.

The surface area is 4,260 acres (17.24 km2; 6.66 sq mi), of which approximately two-thirds is in Wisconsin and one third in Michigan.

They translated the name into French from the term used by the Ojibwe of the area: Gete-gitigaani-zaaga'igan, meaning "Lake of the Old Clearing", or "Old Garden."

At the time of European colonization, the Ojibwe (also known in the US as Chippewa) occupied extensive territory around Lake Superior, in what are now the jurisdictions of northern Michigan, Wisconsin and Minnesota in the United States, and northern Ontario through southeastern Manitoba in Canada.

Most of the shoreline on the Wisconsin side of the lake is developed, however dense forest surrounds many of the properties.