Lake Winnebago

Lake Winnebago
From space on March 28, 2022 (partial ice cover)
Lake Winnebago
Lake Winnebago
LocationWinnebago, Calumet, and Fond du Lac counties,
Wisconsin
Coordinates44°00′45″N 88°25′03″W / 44.01250°N 88.41750°W / 44.01250; -88.41750
Primary inflowsWolf River, Fox River
Primary outflowsFox River
Basin countriesUnited States
Max. length30 miles (50 km)
Max. width10 miles (15 km)
Surface area131,939 acres (206.155 sq mi; 533.94 km2)
Average depth15.5 ft (4.7 m)
Max. depth21 ft (6.4 m)
Surface elevationabout 746 ft (227 m)
above sea level
SettlementsOshkosh, Fond du Lac, Neenah and Menasha

Lake Winnebago (Menominee: Wenepekōw Nepēhsæh, Ojibwe: Wiinibiigoo-zaaga'igan, Oneida: kanyataláheleˀ) is a shallow freshwater lake in the north central United States, located in east central Wisconsin. At 137,700 acres (55,700 ha), it is the largest lake entirely within the state, covering an area of about 30 miles (48 km) by 10 miles (16 km) with 88 miles (142 km) of shoreline, an average depth of 15.5 feet (4.7 m), and a maximum depth of 21 feet (6.4 m). It has many shallow reefs along the west shore and a drop-off type shoreline on the east. There are several islands along the west shore.

The lake has two primary tributaries, the Wolf and Fox Rivers, which combine at Lake Butte des Morts. The Fox River flows east through Oshkosh and into Lake Winnebago at its west central shore, then flows out at the northwest shore, around Doty Island at Neenah-Menasha to Little Lake Butte des Morts. The river then flows northeast and empties into Green Bay and serves as part of the Fox-Wisconsin Waterway. Lake Winnebago is part of a larger system of lakes in Wisconsin known as the Winnebago Pool.

Cities on its shores include the aforementioned Oshkosh, Neenah, and Menasha, as well as Fond du Lac at the south shore. Municipal drinking water systems serving over 200,000 people draw directly from the lake, including systems serving the cities of Oshkosh, Neenah, Menasha, and Appleton.