The answer is…. complicated.
The most common source of hydrography (rivers, streams, lakes) data in Wisconsin is the Wisconsin DNR’s “24k hydro” database. The DNR 24k hydro dataset is the most common starting place for most users in the state. Because the DNR data are limited to Wisconsin, users who need entire watersheds that cross the state border should investigate the National Hydrography Dataset (NHD) maintained by the U.S. Geological Survey.
Where to find the “best” lake map is a common question we receive each spring as fishing season approaches. Start here for more information on lake and lake depth (bathymetric) maps.
While there is no single “best” source we can suggest, there are a number of options you can explore.