Little St Germain Lake

On the LakeGrade scale Little St Germain Lake grades a B, with clarity at 11.5 ft and 45 µg/L of phosphorus placing it above the Wisconsin median. 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. At 53 ft of maximum depth, Little St Germain Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. The lake's 972 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. Little St Germain Lake ranks 189 of 202 in Vilas County — at the lower end of the locally monitored distribution.

Eurasian watermilfoil is established at Little St Germain Lake, which can dampen recreational access and pressure the native plant community. Walleye are documented at Little St Germain Lake, one of 6 fish species on record for the lake. A documented public access point at Little St Germain 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.