Jenny Lake

Jenny Lake sits at the top of the Minnesota PCA grading rubric with an A, a mark reached by the cleanest lakes in Minnesota. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

Trophically, Jenny Lake reads as oligotrophic — nutrient-poor, clear, and ecologically more sensitive to disturbance than richer lakes. Jenny Lake is unusually deep for Minnesota at 93 ft, which buffers the lake against summer warming and helps the deep water stay oxygenated. Jenny Lake covers 102 acres alongside 4.4 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Among the 142 graded lakes in Lake County, Jenny Lake ranks 4 — in the top quartile locally.

Jenny Lake has no invasive species recorded in Minnesota state databases as of 2021, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Jenny Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. The lake lacks a documented public access point, so visitor use is limited. 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.