Sauk Lake

The LakeGrade rubric puts Sauk Lake at a C: clarity at 3.5 ft, 49 µg/L of phosphorus, and a TSI of 60 signal an intermediate trophic state. Sub-grades cluster within a single letter of each other, which usually means the lake is in stable trophic balance rather than fighting one specific stressor.

A TSI in the eutrophic range signals a lake doing what nutrient-loaded waters do — supporting an active algal community at the cost of clear water. The lake's 61 ft maximum depth is in the upper tier for Minnesota — deep enough for cold-water fish to find refuge in summer. With 2,126 acres of surface and 22.3 miles of shoreline, Sauk Lake is a large water by Minnesota standards — recreational pressure is spread across a long shoreline. Sauk Lake sits at rank 33 of 55 in Stearns County, in the lower half of the local distribution.

Zebra mussel presence at Sauk Lake means the lake's clarity numbers carry an asterisk — filtered water is not the same as nutrient-poor water. Walleye are documented at Sauk Lake, one of 18 fish species on record for the lake. Public access is available — the lake is on the Minnesota PCA public-access list. The lake has a partial ice record — 13 observed ice-outs, centered near Apr 7. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.