Brown Lake

The LakeGrade rubric puts Brown Lake at a C: clarity at 7.0 ft, phosphorus readings still being added, and a TSI of 49 signal an intermediate trophic state.

Mesotrophic conditions dominate at Brown Lake: enough nutrients for a healthy fishery, not so much that algal blooms become a chronic problem. A maximum depth of 28 ft puts Brown Lake in the middle of Minnesota's depth distribution. Brown Lake is small — 68 acres alongside 1.6 miles of shoreline — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Within Aitkin County's 53 graded lakes, Brown Lake ranks 29 — below the local median, though not at the bottom.

Brown Lake has no invasive species recorded in Minnesota state databases as of 2021, though prevention practices still apply at all access points. The fishery is bass-led, with 10 documented species across the lake's records. 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.