Lost Lake

The LakeGrade rubric puts Lost Lake at a C: clarity at 6.3 ft, 25 µg/L of phosphorus, and a TSI of 49 signal an intermediate trophic state. Clarity is the limiting factor — phosphorus is reasonable but suspended particles or algal cells keep water transparency below Minnesota norms.

A TSI near 49 places Lost Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. A maximum depth of 34 ft puts Lost Lake in the middle of Minnesota's depth distribution. Lost Lake is small — 63 acres alongside 1.6 miles of shoreline — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Among the 83 graded lakes in Washington County, Lost Lake sits at rank 32, above the county median.

Zebra mussel presence at Lost Lake means the lake's clarity numbers carry an asterisk — filtered water is not the same as nutrient-poor water. Bass fishing is part of the appeal: the species list runs to 11, anchored by largemouth and/or smallmouth bass. The lake lacks a documented public access point, so visitor use is limited. Multiple sampling years from Minnesota PCA volunteers and partner agencies back the grade, so the letter should hold steady absent a major watershed shift.