Turtle Lake

On the LakeGrade rubric, Turtle Lake pulls an A: clarity at 36.1 ft and 15 µg/L of phosphorus put it in the top bracket for Wisconsin. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

A TSI value of 34 puts Turtle Lake in the oligotrophic range, where biological productivity stays low and the water column remains clear. Turtle Lake reaches 30 ft at its deepest point — typical for Wisconsin mid-sized lakes, with seasonal stratification but limited cold-water refuge. The lake's 141 acres and partial shoreline records put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Turtle Lake ranks 5 of 34 in Walworth County, putting it in the upper tier of locally monitored lakes.

Turtle Lake is on the Wisconsin infested-waters list for zebra mussels — boaters should follow clean-drain-dry protocols when moving gear to or from the lake. Bass fishing is part of the appeal: the species list runs to 3, anchored by largemouth and/or smallmouth bass. Public access is available — the lake is on the Wisconsin DNR public-access list. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.