2006 image from space
|Location||Winnebago / Calumet / Fond du Lac counties, Wisconsin, USA|
|Primary inflows||Wolf River, Fox River|
|Primary outflows||Fox River|
|Basin countries||United States|
|Surface area||137,700 acres (55,700 ha)
(215 sq. mi / 557 km²)
|Average depth||15.5 ft (4.7 m)|
|Max. depth||21 ft (6.4 m)|
|Surface elevation||about 746 feet above sea level|
|Settlements||Oshkosh, Fond du Lac, Neenah and Menasha|
Lake Winnebago is a 137,700-acre (55,700 ha) freshwater lake in eastern Wisconsin, United States. It is the largest lake entirely within the state and one of the largest inland lakes in the United States. Lake Winnebago is about 30 by 10 miles (48 by 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).
Lake Winnebago has two primary tributaries, the Wolf River and the Fox River. It is drained by the Fox River which flows north towards 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 Oshkosh, Fond du Lac, Neenah and Menasha. Municipal drinking water systems serving over 250,000 people draw directly from the lake, including systems serving the cities of Oshkosh, Neenah, Menasha and Appleton.
The lake is a remnant of Glacial Lake Oshkosh approximately 12,000 years ago. Ice blocked water from entering Lake Michigan at Green Bay, and the glacial lake ponded against ice since it had no outlet.
The Niagara Escarpment is a few miles east of Lake Winnebago. The softer Ordovician rocks that underlie the lake have eroded away, and the stronger Silurian rocks stand as a ridge that formed the lake basin.
In 1634, the French discovered the Winnebago Indian tribe on the shores of Green Bay, Wisconsin, inhabiting the area stretching to Lake Winnebago. Although "Ho-Chunk" is the people's own name for themselves, their Algonquian neighbors called them "Winnebago", which means "people of the filthy water". This term was used by the Algonquians because Lake Winnebago had a strong fish odor in the summer.
The steamer B. F. Carter made a trip from the east shore to the west shore at Oshkosh every two weeks in the 1880s during the summer season.
Lake Winnebago is known for having occasional ice shoves on very windy days in March as the winter ice breaks up. Residents have described that it "sounds like a freight train." Buildings on the shore have been wrecked by the shoves, which are up to 25 feet high.
Locks and dams 
Lake Winnebago is not man-made, but its level was raised about three feet by two dams on either side of Doty Island, erected in 1850 and 1930. The lake level is today regulated by the US Army Corps of Engineers to meet demands for flood control, to reduce ice damage to private property, to release water for hydropower and pollution dilution downstream, and to extend the high water season for boating.
A system of seventeen locks connects Lake Winnebago to Lake Michigan. This lock system is located along the lower Fox River and starts at the northwest corner of Lake Winnebago in the city of Menasha and ends at the mouth of Green Bay. One of the locks, the Rapid Croche Lock, is permanently sealed as a barrier to prevent the movement of sea lamprey upstream, and only three of the remaining locks were being maintained. Lock reconstruction is underway and is being supervised by the Fox River Navigation Authority.
Many annual events take place on the Winnebago Pool, including shoreline concerts, fishing tournaments, power boat events, pleasure boating rallies, sail runs and ice racing.
Along with the upper lakes of Big Lake Butte des Morts, Winneconne, Poygan, the Wolf River and the upper and lower Fox River, it is a popular pleasure boating area. A 1989 survey of boating intensity by the Wisconsin Department of Natural Resources ranked the Winnebago Pool as the state's busiest inland waterway, surpassing the Mississippi River.
Lake Winnebago has a variety of state, county and city parks. High Cliff State Park is the only state park on Lake Winnebago, in the lake's northeast corner. The park offers camping, hiking trails, beautiful views of the lake, a marina, beach, observation tower and picnic areas. Camping is available at Calumet County Park and Columbia County Park in Fond du Lac County. Visitors can see effigy mounds that overlook the lake at High Cliff and Calumet County Park.
Lakeside Park in Fond du Lac is on the southern border of Lake Winnebago and has a variety of attractions on the 400-acre (1.6 km2) lot including picnic areas, shelters/gazebos, playground, deer park, ball diamonds, marina, and boat launch ramps. Train rides, an old fashioned carousel, bumper boats, aqua bikes, and canoes are available for rides. A petting zoo is also open Memorial Day weekend through Labor Day. The main park in Oshkosh is Menominee Park, which features trails, fishing piers, boat launches, a zoo, a small amusement park, softball, tennis and basketball facilities. Menominee Park is the site of the city's Sawdust Days Festival in July.
Lake Winnebago is one of the more heavily fished lakes in the state. Many fishermen consider it one of the nation's top walleye fisheries. Other species present include bluegill, largemouth bass, muskellunge, northern pike, perch, burbot, white bass, freshwater drum, channel catfish, flathead catfish, and smallmouth bass. In June 2010, Oshkosh hosted an event recognized by Guinness World Records as history's largest fishing tournament. A 2007 study put the economic value of recreational fishing at approximately $300 million per year.
Ice fishing is popular on Lake Winnebago. It is not uncommon for 10,000 cars to park on Lake Winnebago during the ice fishing season. Expansion cracks on the ice are bridged, and many cities along the east and west shores plow roads on the icy surface. Sauger and walleye predominate, with rare perch and white bass catches.
The spearfishing season for lake sturgeon is in February. The first year of regulated sturgeon spearing was 1903, when an eight-pound limit was introduced. All sturgeon spearing was banned from 1915 to 1931. The lake had the largest population of sturgeon in the United States in 2003. The Wisconsin Department of Natural Resources regulates the number of fish taken each year.
Other seasons 
Early spring (between May 5 and June 30) is dominated by walleye and sauger fishing. Sauger, also known as sand pike, bite the best in cooler water. June fishing is the peak time for white bass, and July for perch. Fishing declines in fall.
- Folz, Dan (January 1989). Fishing Lake Winnebago. Wisconsin Department of Natural Resources.
- Lakes, United States Department of the Interior, Retrieved September 21, 2008
- Lake Oshkosh Drainage; Steven Dutch; Natural and Applied Sciences; University of Wisconsin–Green Bay; Last updated April 29, 2005; Retrieved January 14, 2007
- The Niagara Escarpment; Steven Dutch; Natural and Applied Sciences; University of Wisconsin–Green Bay; Last updated June 18, 1999; Retrieved January 14, 2007
- William J. Kubiak (Great Lakes Indians) Grand Rapids: Baker Book House Company, 1970
- Page 8 (2007-05-17), Looking Back, Chilton Times Journal
- "`Ice Shoves' Along Lake Winnebago Cause Damage". WSAW-TV. Retrieved January 21, 2013.
- Doran, Chad. "Ice shoves cause damage on Lake Winnebago shoreline". WLUK-TV. Retrieved January 21, 2013.
- Bergquist, Lee (February 7, 2003). With spearing season ahead, fish in Lake Winnebago system could number up to 50,000. Archived from the original on 2007-03-10. Retrieved 2007-01-14.
|Wikimedia Commons has media related to: Lake Winnebago|
- Current lake data from the United States Army Corps of Engineers
- Fishing maps and data from Lake-Link.com
- Glacial Lake Oshkosh