Lost Lake

The LakeGrade rubric puts Lost Lake at a C: clarity at 6.0 ft, 25 µg/L of phosphorus, and a TSI of 51 signal an intermediate trophic state. 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. The lake's surface area is not consistently recorded across state datasets — physical context remains partial. Within Polk County's 74 graded lakes, Lost Lake ranks 43 — below the local median, though not at the bottom.

No invasive species are currently listed at Lost Lake — the lake remains off the Wisconsin infested-waters roster. The state fisheries records do not list documented species for Lost Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. 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.