Lake Size: 8800 acres
Deepest Depth: 9 ft
Latitude: 44.0423
Longitude: -88.3831
Lake Level Above Sea Level: 747 ft
Counties: Winnebago County
Cities: Omro Area

Information: Big Lake Butte des Morts (pronounced /ˌbjuːdəˈmɔər/[1]) is an 8,800-acre (36 km2) lake located in the U.S. state of Wisconsin and is part of the Winnebago Pool (also known as the Winnebago System). The lake is fed by the Fox River in the southwest and the Wolf River draining from Lake Winneconne in the northwest, and drains via the Fox River southeast into Lake Winnebago. The lake is also part of the Butte des Morts region in Winnebago County, Wisconsin. Much of the lake is flooded marshland created by the damming of the Fox River downstream in Menasha in the 1800s, which explains the lake's flat and shallow character (maximum depth is 9 ft). U.S. Route 41 spans the east end of the lake via. a bridge and causeway combination. The city of Oshkosh, Wisconsin lies between Lake Butte des Morts and Lake Winnebago. Big Lake Butte des Morts is popular among both fishermen and recreational boaters during the warm months, and with ice fishermen in the winter. A marked navigation channel helps passage across the lake from the inflow of the Wolf River to the west (connecting to Lake Poygan), to the outflow of the Fox River east to Lake Winnebago. While in the same general location, it is not connected to Little Lake Butte des Morts, a smaller lake to the north downstream of the Winnebago Pool. Big Lake Butte des Morts served as part of the Fox-Wisconsin Waterway.