Missionary Lake

Missionary Lake sits at the top of the Minnesota PCA grading rubric with an A, a mark reached by the cleanest lakes in Minnesota. 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.

Trophically, Missionary Lake reads as oligotrophic — nutrient-poor, clear, and ecologically more sensitive to disturbance than richer lakes. At 71 ft of maximum depth, Missionary Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. At 99 acres, Missionary Lake sits below the Minnesota median: a small water where shoreline activity has an outsized effect on water quality. Within Lake County's 142 graded waters, Missionary Lake sits at rank 11, near the top of the local distribution.

No invasive species are currently listed at Missionary Lake — the lake remains off the Minnesota infested-waters roster. The state fisheries records do not list documented species for Missionary 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.