Long Lake

Long Lake earns a D — measurements through 2024 show persistent nutrient pressure that limits clarity through the summer. 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.

Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. Long Lake reaches 24 ft at its deepest point — typical for Minnesota mid-sized lakes, with seasonal stratification but limited cold-water refuge. The lake is compact at 77 acres, with 2.5 miles of shoreline and little volume to buffer nutrient inputs. Within Pine County's 19 graded lakes, Long Lake ranks 13 — below the local median, though not at the bottom.

No invasive species are currently listed at Long Lake — the lake remains off the Minnesota infested-waters roster. The fishery is bass-led, with 13 documented species across the lake's records. A documented public access point at Long Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.