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.

A TSI value of 36 puts Missionary Lake in the oligotrophic range, where biological productivity stays low and the water column remains clear. Missionary Lake is unusually deep for Minnesota at 71 ft, which buffers the lake against summer warming and helps the deep water stay oxygenated. 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. No formal public access is documented at Missionary Lake — most use is by shoreline residents and their guests. 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.