Hiawatha Lake

Hiawatha Lake sits at the top of the Wisconsin DNR grading rubric with an A, a mark reached by the cleanest lakes in Wisconsin. 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 near 43 places Hiawatha Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. At 58 ft of maximum depth, Hiawatha Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. At 36 acres, Hiawatha Lake sits below the Wisconsin median: a small water where shoreline activity has an outsized effect on water quality. Within the 202 graded lakes of Vilas County, Hiawatha Lake sits at rank 164, near the bottom of the county list.

No invasive species are currently listed at Hiawatha Lake — the lake remains off the Wisconsin infested-waters roster. Walleye are documented at Hiawatha Lake, one of 3 fish species on record for the lake. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.