- Area: 8,581 Acres
- Max Depth: 9 feet
- County: Winnebago
Big Lake Butte des Morts, or “Hill of the Dead” in French, is named for a hill overlooking the lake where a town of the same name sits. Hill was so named because Native Americans buried their dead there. The town was once one of the major settlements of the state because it was the intersection of several early trade routes. The town’s importance was soon surpassed by others however, and remains a small community.
Of all the Winnebago Upper Pool Lake, Lake Butte des Morts has the most remaining aquatic vegetation, both submergent and emergent. Major emergent vegetation is Hardstem Bulrush, and Phragmites, which form the cane beds. In addition, there is Stiff Arrowhead, and a tiny and annually variable, wild rice.
Methods to reduce the habitat loss on lake Butte des Morts and the other Upper Pool lakes began more than a century ago by driving wooden piles into floating mats of vegetation. The floating mats were prone to ripping out during floods, spring thaw, and wind storms. The piles worked for a time, but eventually, the floating mats floated away towards Oshkosh, and Lake Winnebago.
To prevent the marsh from eroding a number of hard armor strategies were devised. The early ones involved dumping whatever was handy along the marsh edge, notably old car bodies. Most of the cars were removed and rock rip rap was used. This was largely effective, but produced an unnatural barrier between the lake and the wetlands. Today most of the wetlands along Lake Butte des Morts are armored and wetland loss greatly reduced.
Habitat is also lost in the name of progress. Recently a reconstruction project of Hwy 41 filled in part of the lake bed to make room for additional lanes on the bridge. Perhaps it couldn’t be helped, but at least they added some beauty to a man-made structure. By law, the Department of Transportation had to create a new wetland, or improve an existing one to make up for the loss of lake from the fill, a process called mitigation. The DOT has begun work at Terrell’s Island to improve wetland habitat there. It is always preferable that mitigation occurs in the same area as the damage.
Links and References
The Butte des Morts Conservation Club co-manages Terrell’s Island (open to the public) with the Wisconsin Department of Natural Resources to improve the wetlands and promote environmental education. It is a great conservation organization and I strongly recommend becoming a member or contributor.