Trease Lake

Trease Lake sits at a C on the grading scale — not impaired, not pristine, with summer measurements that vary year to year. The lake's weakest score is on Secchi depth — the water looks more turbid than its phosphorus number alone would predict.

Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. Trease Lake is small — 97 acres alongside 4.8 miles of shoreline — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Trease Lake sits at rank 127 of 187 in St. Louis County, in the lower half of the local distribution.

No invasive species are currently listed at Trease Lake — the lake remains off the Minnesota infested-waters roster. The fishery is bass-led, with 4 documented species across the lake's records. No formal public access is documented at Trease 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.