Hilbert Lake

Hilbert Lake sits at the top of the Wisconsin DNR grading rubric with an A, a mark reached by the cleanest lakes in Wisconsin. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

A TSI value of 33 puts Hilbert Lake in the oligotrophic range, where biological productivity stays low and the water column remains clear. The lake bottoms out at 32 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. Hilbert Lake covers 278 acres alongside partial shoreline records — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Hilbert Lake ranks 17 of 22 in Marinette County — at the lower end of the locally monitored distribution.

Hilbert Lake has at least one documented invasive species (Rusty Crayfish), so boaters and anglers should observe clean-drain-dry steps when leaving the lake. The fishery includes walleye alongside the lake's other 5 documented species — a notable draw for Wisconsin anglers. A documented public access point at Hilbert Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.