Little Mary Lake

Little Mary Lake grades an F: water clarity, phosphorus, and chlorophyll-a all rate poorly, placing it among the most stressed lakes monitored in Minnesota. Sub-grades cluster within a single letter of each other, which usually means the lake is in stable trophic balance rather than fighting one specific stressor.

The hypereutrophic status — TSI 74 — reflects sustained heavy nutrient loading from the surrounding watershed and frequent algal pressure. 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. Little Mary Lake ranks 60 of 64 in Wright County — at the lower end of the locally monitored distribution.

Eurasian watermilfoil has been documented at Little Mary Lake, requiring shoreline management to keep dense mats from crowding native vegetation. The state fisheries records do not list documented species for Little Mary Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. A documented public access point at Little Mary Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. 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.