Middle Sugarbush Lake

Middle Sugarbush 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 value of 31 puts Middle Sugarbush Lake in the oligotrophic range, where biological productivity stays low and the water column remains clear. The lake's 57 ft maximum depth is in the upper tier for Wisconsin — deep enough for cold-water fish to find refuge in summer. Middle Sugarbush Lake covers 254 acres alongside partial shoreline records — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Among the 202 graded lakes in Vilas County, Middle Sugarbush Lake ranks 2 — in the top quartile locally.

An invasive species record — Rusty Crayfish — has been logged at Middle Sugarbush Lake; Wisconsin DNR maintains the official infested-waters list. Walleye are documented at Middle Sugarbush Lake, one of 6 fish species on record for the lake. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.