Holly Lake

On the scoring rubric Holly Lake grades a D: clarity at 4.9 ft and phosphorus readings still being added keep it in the lower bracket for Cook County. 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. A maximum depth of just 6 ft means sediment-bound phosphorus releases back into the water column whenever wind stirs the bottom — a classic shallow-lake dynamic. The lake is compact at 76 acres, with 1.8 miles of shoreline and little volume to buffer nutrient inputs. Holly Lake ranks 103 of 128 in Cook County — at the lower end of the locally monitored distribution.

No invasive species are currently listed at Holly Lake — the lake remains off the Minnesota infested-waters roster. The fishery includes walleye alongside the lake's other 5 documented species — a notable draw for Minnesota anglers. A documented public access point at Holly Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The lake has a partial ice record — 5 observed ice-outs, centered near May 8. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.