Lake Winnibigoshish

Lake Winnibigoshish sits at the top of the Minnesota PCA grading rubric with an A, a mark reached by the cleanest lakes in Minnesota. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

The lake sits in the mesotrophic zone — the band where most well-managed Minnesota lakes fall. Lake Winnibigoshish is unusually deep for Minnesota at 70 ft, which buffers the lake against summer warming and helps the deep water stay oxygenated. Lake Winnibigoshish covers 56,471 acres alongside 69.8 miles of shoreline, large enough that conditions can vary meaningfully between bays. Lake Winnibigoshish sits at rank 82 of 133 in Cass County, in the lower half of the local distribution.

Lake Winnibigoshish is on the Minnesota infested-waters list for zebra mussels — boaters should follow clean-drain-dry protocols when moving gear to or from the lake. Muskie are on the species list at Lake Winnibigoshish, alongside the lake's 20 other documented fish. Public access is available — the lake is on the Minnesota PCA public-access list. The lake has a long ice-out record — 30 observations on file, with a median ice-out around Apr 27. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.