The Winnebago Pool is a collective name for a group of interconnected lakes in eastern Wisconsin. The Winnebago Pool includes Lake Winnebago, Big Lake Butte des Morts, Lake Poygan and Lake Winneconne. These lakes combined encompass over and account for nearly 17% of the total surface water area in Wisconsin (not counting the Great Lakes). They generally have a water surface elevation of about 746, some 170 feet above the Bay of Green Bay which is about 39 river miles to the northeast. The primary feed waters of the Winnebago Pool are the Wolf River, Fox River and Fond du Lac River. Lakes Winnebago and Big Lake Butte des Morts (along with Little Lake Butte des Morts to the northeast) served as part of the Fox-Wisconsin Waterway.