Greenwood Lake

On the LakeGrade rubric, Greenwood Lake pulls an A: clarity at 14.8 ft and 8 µg/L of phosphorus put it in the top bracket for 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 lake's low TSI puts it in oligotrophic territory — the cleanest of the four trophic classes, but also the most vulnerable to nutrient-driven shifts. Greenwood Lake is unusually deep for Minnesota at 112 ft, which buffers the lake against summer warming and helps the deep water stay oxygenated. At 2,043 acres, Greenwood Lake is one of the larger lakes in Cook County, with 23.4 miles of shoreline supporting multiple distinct use patterns. Among the 128 graded lakes in Cook County, Greenwood Lake sits at rank 36, above the county median.

Greenwood Lake has at least one documented invasive species (spiny waterflea), so boaters and anglers should observe clean-drain-dry steps when leaving the lake. The fishery is bass-led, with 10 documented species across the lake's records. A documented public access point at Greenwood Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The lake has a partial ice record — 21 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.