Spirit Lake

Spirit Lake carries a solid B grade — strong on most parameters, with measurements that hold up well across the summer season. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

The lake sits in the mesotrophic zone — the band where most well-managed Wisconsin lakes fall. Spirit Lake reaches 20 ft at its deepest point — typical for Wisconsin mid-sized lakes, with seasonal stratification but limited cold-water refuge. At 73 acres, Spirit Lake sits below the Wisconsin median: a small water where shoreline activity has an outsized effect on water quality. Within Vilas County's 191 graded lakes, Spirit Lake ranks 104 — below the local median, though not at the bottom.

Spirit Lake has no invasive species recorded in Wisconsin state databases as of 2024, though prevention practices still apply at all access points. The lake's fish records list 1 species — a varied community without one dominant gamefish. 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.