Lake Wisconsin
A flowage in Wisconsin
7,197 acres
About Lake Wisconsin
Lake Wisconsin covers 7,197 acres in Columbia and Sauk counties, backed up behind the dam at Prairie du Sac on the Wisconsin River. It runs nearly thirteen miles and carries 54 miles of shoreline, taking in Okee, Harmony Grove and Moon Valley along the way.
Fifteen public landings serve it — a generous number, and a reminder that this is the most heavily used water on the lower Wisconsin River, within easy reach of Madison.
The state's only fisheries designation here is smallmouth bass, classified as non-wadable fine substrate, which describes a broad soft-bottomed impoundment rather than a rocky one. That single classification understates what people fish for on it.
An impoundment on a big river is shaped by the drowned channel underneath it, and by how much water the dam is passing on any given day. Check the current DNR regulations before keeping fish.
Written from Wisconsin DNR hydrography and fisheries data. State water ID WBIC 1260600.
How the state manages it
- smallmouth · Non-Wadable Fine Substrate
Wisconsin DNR fisheries designations. These describe how the water is managed, not what is in it on any given day.
Fishing license
Wisconsin sells them online. Buy one from the state. We don’t know whether you need one — that depends on your age, where you live, the water, and what your guide’s own license covers.